# Meson Particle Listings

$f_0(980)$

$f_0(980)$

$I^G(J^PC) = 0^+(0++)$

See the related review(s):

Scalar Mesons below 1 GeV

## $f_0(980)$ T-MATRIX POLE $\sqrt{s}$

Note that $\Gamma = -2 \text{Im}(\sqrt{s})$.

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td colspan="4"><strong>(980-1010) - i (20-35) OUR ESTIMATE</strong> (see Fig. 64.4 in the review)</td></tr><tr><td>(993 ± 2<sup>+2</sup><sub>-1</sub>) - i(21 ± 3<sup>+2</sup><sub>-4</sub>)</td><td>1 DANILKIN</td><td>21</td><td>RVUE Compilation</td></tr><tr><td>(1014 ± 8) - i(35 ± 5)</td><td>SARANTSEV</td><td>21</td><td>RVUE J/ψ(1S) → γ (ππ, K<sup>π</sup>, ηη, ωφ)</td></tr><tr><td>(992.8 ± 1.3) - i(30.7 ± 2.3)</td><td>2 ALBRECHT</td><td>20</td><td>RVUE 0.9 p̄p → π<sup>0</sup>π<sup>0</sup>ηη, π<sup>0</sup>ηη, π<sup>0</sup>K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>(1003<sup>+5</sup><sub>-27</sub>) - i(21<sup>+10</sup><sub>-8</sub>)</td><td>3 GARCIA-MAR..11</td><td></td><td>RVUE Compilation</td></tr><tr><td>(996 ± 7) - i(25<sup>+10</sup><sub>-6</sub>)</td><td>4 GARCIA-MAR..11</td><td></td><td>RVUE Compilation</td></tr><tr><td>(996<sup>+14</sup><sub>-10</sub>) - i(24<sup>+11</sup><sub>-3</sub>)</td><td>5 MOUSSALLAN11</td><td></td><td>RVUE Compilation</td></tr><tr><td>(981 ± 43) - i(18 ± 11)</td><td>6 MENNESSIER</td><td>10</td><td>RVUE Compilation</td></tr><tr><td>(1030<sup>+30</sup><sub>-10</sub>) - i(35<sup>+10</sup><sub>-16</sub>)</td><td>7 ANISOVICH</td><td>09</td><td>RVUE 0.0 p̄p, πN</td></tr><tr><td>(973<sup>+39</sup><sub>-127</sub>) - i(11<sup>+19</sup><sub>-11</sub>)</td><td>8 PELAEZ</td><td>04A</td><td>RVUE ππ → ππ</td></tr></tbody></table>

1. Data driven analysis using partial-wave dispersion relations.

2. 5 poles, 5 channels, including scattering data from HYAMS 75 (ππ), LONGACRE 86 (K$\bar{K}$), BINON 83 (ηη), and BINON 84c (ηη'). Based on 18.5k events. Second solution 977.8 ± 1.7 MeV.

3. Reanalysis of the $K_{e4}$ data of BATLEY 10C and the $πN → ππN$ data of HYAMS 73, GRAYER 74, and PROTOPOPESCU 73 using Roy equations.

4. Reanalysis of the $K_{e4}$ data of BATLEY 10C and the $πN → ππN$ data of HYAMS 73, GRAYER 74, and PROTOPOPESCU 73 using GKPY equations.

5. Uses Roy equations.

6. Average of the analyses of three data sets in the K-matrix model. Uses the data of BATLEY 08a, HYAMS 73, and GRAYER 74, partially of COHEN 80 or ETKIN 82b.

7. On sheet II in a 2-pole solution. The other pole is found on sheet III at (850 - i 100) MeV.

8. Reanalysis of data from PROTOPOPESCU 73, ESTABROOKS 74, GRAYER 74, and COHEN 80 in the unitarized ChPT model.

## $f_0(980)$ MASS

<table><thead><tr><th>VALUE (MeV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td><strong>990 ±20</strong></td><td><strong>OUR ESTIMATE</strong></td><td></td><td></td><td></td></tr><tr><td>992.0 ± 8.5</td><td>8.5 ± 8.6</td><td>1 AAIJ</td><td>19H LHCB</td><td>pp → D<sup>±</sup>X</td></tr><tr><td>989.4 ± 1.3</td><td>424</td><td>ABLIKIM</td><td>15P BES3</td><td>J/ψ → K<sup>+</sup>K<sup>-</sup> 3π</td></tr><tr><td>989.9 ± 0.4</td><td>706</td><td>ABLIKIM</td><td>12E BES3</td><td>J/ψ → γ3π</td></tr><tr><td>977 ± 11</td><td>1 ± 1</td><td>2 ECKLUND</td><td>09 CLEO</td><td>4.17 e<sup>+</sup>e<sup>-</sup> → D<sub>S</sub><sup>+</sup>K<sub>S</sub><sup>+</sup> + c.c.</td></tr><tr><td>982.2 ± 1.0</td><td>8.1</td><td>3 UEHARA</td><td>08A BELL</td><td>10.6 e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>0</sup>π<sup>0</sup></td></tr><tr><td>976.8 ± 0.3</td><td>10.1 ± 0.6</td><td>4 AMBROSINO</td><td>07 KLOE</td><td>1.02 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>η</td></tr><tr><td>984.7 ± 0.4</td><td>2.4</td><td>5 AMBROSINO</td><td>07 KLOE</td><td>1.02 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>η</td></tr><tr><td>973 ± 3</td><td>262 ± 30</td><td>6 AUBERT</td><td>07AKBABR</td><td>10.6 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>π<sup>-</sup>γ</td></tr><tr><td>970 ± 7</td><td>54 ± 9</td><td>6 AUBERT</td><td>07AKBABR</td><td>10.6 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>π<sup>-</sup>γ</td></tr><tr><td>953 ± 20</td><td>2.6k</td><td>7 BONVICINI</td><td>07 CLEO</td><td>D<sup>+</sup> → π<sup>-</sup>π<sup>+</sup>π<sup>+</sup></td></tr><tr><td>985.6 ± 1.2</td><td>1.1</td><td>8 MORI</td><td>07 BELL</td><td>10.6 e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>-</sup></td></tr><tr><td>983.0 ± 0.6</td><td>4.0</td><td>9 AMBROSINO</td><td>06B KLOE</td><td>1.02 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>977.3 ± 0.9</td><td>3.7</td><td>10 AMBROSINO</td><td>06B KLOE</td><td>1.02 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>950 ± 9</td><td>4286</td><td>11 GARMASH</td><td>06 BELL</td><td>B<sup>+</sup> → K<sup>+</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>965 ± 10</td><td></td><td>12 ABLIKIM</td><td>05 BES2</td><td>J/ψ → φπ<sup>+</sup>π<sup>-</sup>, φK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1031 ± 8</td><td></td><td>13 ANISOVICH</td><td>03 RVUE</td><td></td></tr><tr><td>1037 ± 31</td><td></td><td>TIKHOMIROV</td><td>03 SPEC</td><td>40.0 g<sup>-</sup><sub>S</sub>C<sup>-</sup><sub>S</sub>K<sub>S</sub><sup>0</sup>K<sub>S</sub><sup>0</sup>X</td></tr><tr><td>973 ± 1</td><td>2438</td><td>14 ALOISIO</td><td>02D KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>977 ± 3 ± 2</td><td>848</td><td>15 AITALA</td><td>01A E791</td><td>D<sub>S</sub><sup>+</sup> → π<sup>-</sup>π<sup>+</sup>π<sup>+</sup></td></tr><tr><td>969.8 ± 4.5</td><td>419</td><td>16 ACHASOV</td><td>00H SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>985 ± 16</td><td>171.18</td><td>17 ACHASOV</td><td>00H SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>976 ± 5 ± 6</td><td></td><td>19 AKHMETSHIN 99B</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>977 ± 3 ± 6</td><td>268</td><td>19 AKHMETSHIN 99C</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>975 ± 4 ± 6</td><td></td><td>20 AKHMETSHIN 99C</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>975 ± 4 ± 6</td><td></td><td>21 AKHMETSHIN 99C</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ, π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>985 ± 10</td><td></td><td>BARBERIS</td><td>99 OMEG</td><td>450 pp → p<sub>S</sub>p<sub>F</sub>K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>982 ± 3</td><td></td><td>BARBERIS</td><td>99B OMEG</td><td>450 pp → p<sub>S</sub>p<sub>F</sub>π<sup>+</sup>π<sup>-</sup></td></tr></tbody></table>

$982 \pm 3$

$987 \pm 6 \pm 6$

$989 \pm 15$

$991 \pm 3$

$\sim 980$

$\sim 993.5$

$\sim 987$

$957 \pm 6$

$960 \pm 10$

$1015 \pm 15$

$1008$

$955 \pm 10$

$994 \pm 9$

$993.2 \pm 6.5 \pm 6.9$

$1006$

$997 \pm 5$

3k

$960 \pm 10$

10k

$994 \pm 5$

$\sim 996$

$987 \pm 6$

$1015$

$983$

$973 \pm 2$

$988$

$988 \pm 10$

$971.1 \pm 4.0$

$979 \pm 4$

$956 \pm 12$

$959.4 \pm 6.5$

$978 \pm 9$

$985.0^{+9.0}_{-39.0}$

$974 \pm 4$

$975$

$986 \pm 10$

$969 \pm 5$

$987 \pm 7$

$1012 \pm 6$

$1007 \pm 20$

$997 \pm 6$

$99C$ BARBERIS 99C OMEG 450 pp → $p_S p_F \pi^0 \pi^0$

$99D$ BARBERIS 99D OMEG 450 pp → $K^+ K^-$

$22$ BELLAZZINI 99 GAM4 450 pp → $p p \pi^0 \pi^0$

$23$ KAMINSKI 99 RVUE $\pi \pi \to \pi \pi, K \bar{K}, \sigma \sigma$

$23$ OLLER 99 RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$23$ OLLER 99B RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$24$ OLLER 99C RVUE $\pi \pi \to \pi \pi, K \bar{K}, \eta \eta$

$24$ ACKERSTAFF 98Q OPAL $Z \to f_0 X$

$98$ ALDE 98 GAM4

$23$ ANISOVICH 98B RVUE Compilation

$25$ LOCHER 98 RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$24$ ALDE 97 GAM2 450 pp → $p p \pi^0 \pi^0$

$26$ BERTIN 97C OBLX 0.0 $p \bar{p} p \to \pi^+ \pi^- \pi^0$

$27$ ISHIDA 96 RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$28$ TORNQVIST 96 RVUE $\pi \pi \to \pi \pi, K \bar{K}, K \pi$

$28$ ALDE 95B GAM2 38 $\pi^- p \to \pi^0 \pi^0 n$

$29$ ALDE 95B GAM2 38 $\pi^- p \to \pi^0 \pi^0 n$

$30$ AMSLER 95B CBAR 0.0 $p \bar{p} p \to 3 \pi^0$

$30$ AMSLER 95D CBAR 0.0 $p \bar{p} p \to \pi^0 \pi^0 \pi^0$

$31$ ANISOVICH 95 RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$31$ JANSSEN 95 RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$32$ BUGG 94 RVUE $p \bar{p} p \to \eta 2 \pi^0$

$33$ KAMINSKI 94 RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$34$ ZOU 94B RVUE $\pi \pi \to \pi \pi, K \bar{K}$

$35$ MORGAN 93 RVUE $\pi \pi (K \bar{K}) \to \pi \pi (K \bar{K})$

$35$ MORGAN 93 RVUE $\pi \pi (K \bar{K}) \to \phi \pi \pi (K \bar{K})$

$35$ MORGAN 93 RVUE $J/\psi \to \phi \pi \pi (K \bar{K})$

$35$ MORGAN 93 RVUE $D_S \to \pi(\pi \pi)$

$24$ AGUILAR-... 91 EHS 400 pp

$36$ ARMSTRONG 91 OMEG 300 pp → $p p \pi \pi$, $p p K \bar{K}$

$36$ BREAKSTONE 90 SFM $p p \to p p \pi^+ \pi^-$

$24$ AUGUSTIN 89 DM2 $J/\psi \to \omega \pi^+ \pi^-$

$24$ ABACHI 86B HRS $e^+ e^- \to \pi^+ \pi^- X$

$35$ EKIN 82B MPS 23 $\pi^- p \to n 2 K_S^0$

$36$ GIDAL 81 MRK2 $J/\psi \to \pi^+ \pi^- X$

$37$ ACHASOV 80 RVUE $\pi \pi \to \pi \pi \pi^+ \pi^-$

$36$ AGUILAR-... 78 HBC 0.7 $p \bar{p} p \to K_S^0 K_S^0$

$36$ LEEPER 77 ASPK $2-2.4 \pi^- p \to \pi^+ \pi^- n, K^+ K^- n$

$36$ BINNIE 73 CNTR $\pi^- p \to n \text{MM}$

$38$ GRAYER 73 ASPK $17 \pi^- p \to \pi^+ \pi^- n$

$38$ HYAMS 73 ASPK $17 \pi^- p \to \pi^+ \pi^- n$

$38$ PROTOPOP... 73 HBC $7 \pi^+ p \to \pi^+ p \pi^+ \pi^-$

1. From the $D^\pm \to K^\pm K^+ K^-$ Dalitz plot fit with the Triple-M amplitude in the multi-meson model of AUDEO 18.

2. Using a relativistic Breit-Wigner function and taking into account the finite $D_S$ mass.

3. Breit-Wigner mass. Using finite width corrections according to FLATTE 76 and ACHASOV 05, and the ratio $g_{f_0 K K}/g_{f_0 \pi \pi} = 0$.

4. In the kaon-loop fit.

5. In the no-structure fit.

6. Systematic errors not estimated.

7. FLATTE 76 parameterization. $g_{f_0 \pi \pi} = 329 \pm 96 \text{ MeV}/c^2$ assuming $g_{f_0 K \bar{K}}/g_{f_0 \pi \pi} = 2$.

8. Breit-Wigner mass. Using finite width corrections according to FLATTE 76 and ACHASOV 05, and the ratio $g_{f_0 K K}/g_{f_0 \pi \pi} = 4.21 \pm 0.25 \pm 0.21$ from ABLIKIM 05.

9. In the kaon-loop fit following formalism of ACHASOV 89.

10. In the no-structure fit assuming a direct coupling of $\phi$ to $f_0 \gamma$.

11. FLATTE 76 parameterization. Supersedes GARMASH 05.

12. FLATTE 76 parameterization, $g_{f_0 K \bar{K}}/g_{f_0 \pi \pi} = 4.21 \pm 0.25 \pm 0.21$.

13. K-matrix pole from combined analysis of $\pi^- p \to \pi^0 \pi^0 n, \pi^- p \to K \bar{K} \eta, \pi^+ \pi^- p \to K^+ K^- \pi^0, K_S^0 K_S^0 \pi^0, K^+ K_S^0 \pi^- \text{ at rest}, \bar{p} n \to \pi^- \pi^+ \pi^-, K_S^0 K_S^0 \pi^- \text{ at rest}$.

14. From the negative interference with the $f_0(500)$ meson of AITALA 01B using the ACHASOV 89 parameterization for the $f_0(980)$, a Breit-Wigner for the $f_0(500)$, and ACHASOV 01f for the $\rho \pi$ contribution.

15. Coupled-channel Breit-Wigner, couplings $g_\pi = 0.09 \pm 0.01 \pm 0.01$, $g_K = 0.02 \pm 0.04 \pm 0.03$.

16. Supersedes ACHASOV 98i. Using the model of ACHASOV 89.

17. Supersedes ACHASOV 98i.

18. In the "narrow resonance" approximation.

19. Assuming $\Gamma(f_0) = 40 \text{ MeV}$.

20. From a narrow pole fit taking into account $f_0(980)$ and $f_0(1200)$ intermediate mechanisms.

21. From the combined fit of the photon spectra in the reactions $e^+ e^- \to \pi^+ \pi^- \gamma, \pi^0 \pi^0 \gamma$.

22. Supersedes BARBERIS 99 and BARBERIS 99B.

23. T-matrix pole.

24. From invariant mass fit.

25. On sheet II in a 2 pole solution. The other pole is found on sheet III at (1039-93i) MeV.

26. On sheet II in a 2 pole solution. The other pole is found on sheet III at (963-29i) MeV.

27. Reanalysis of data from HYAMS 73, GRAYER 74, SRINIVASAN 75, and ROSSELET 77 using the interfering amplitude method.

28. At high $|t|$.

29. At low $|t|$.
30 On sheet II in a 4-pole solution, the other poles are found on sheet III at (953–55j) MeV and on sheet IV at (938–35j) MeV.

31 Combined fit of ALDE 95b, ANISOVICH 94, AMSLER 94d.

32 On sheet II in a 2 pole solution. The other pole is found on sheet III at (996–103j) MeV.

33 From sheet II pole position.

34 On sheet II in a 2 pole solution. The other pole is found on sheet III at (797–185j) MeV and can be interpreted as a shadow pole.

35 On sheet II in a 2 pole solution. The other pole is found on sheet III at (978–28j) MeV.

36 From coupled channel analysis.

37 Coupled channel analysis with finite width corrections.

38 Included in AGUILAR-BENITEZ 78 fit.

f₀(980) WIDTH

Width determination very model dependent. Peak width in $\pi\pi$ is about 50 MeV, but decay width can be much larger.

<table><thead><tr><th>VALUE (MeV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td colspan="5"><strong>10 to 100 OUR ESTIMATE</strong></td></tr><tr><td>15.3 ± 4.7</td><td>424</td><td>ABLIKIM</td><td>15P BES3</td><td>J/ψ → K<sup>+</sup>K<sup>-</sup>3π</td></tr><tr><td>9.5 ± 1.1</td><td>706</td><td>ABLIKIM</td><td>12E BES3</td><td>J/ψ → γ3π</td></tr><tr><td>91 <sup>+ 30</sup><sub>- 22</sub> ± 3</td><td>44</td><td>1 ECKLUND</td><td>09 CLEO</td><td>4.17 e<sup>+</sup>e<sup>-</sup> →<br>D<sub>S</sub><sup>-</sup> D<sub>S</sub><sup>+</sup> + C.C.</td></tr><tr><td>66.9 ± 2.2<sup>+17.6</sup><sub>-12.5</sub></td><td></td><td>2 UEHARA</td><td>08A BELL</td><td>10.6 e<sup>+</sup>e<sup>-</sup> →<br>e<sup>+</sup>e<sup>-</sup>π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>65 ± 13</td><td>262 ± 30</td><td>3 AUBERT</td><td>07AK BABR</td><td>10.6 e<sup>+</sup>e<sup>-</sup> →<br>θπ<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>81 ± 21</td><td>54 ± 9</td><td>3 AUBERT</td><td>07AK BABR</td><td>10.6 e<sup>+</sup>e<sup>-</sup> →<br>θπ<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>51.3<sup>+ 20.8</sup><sub>- 17.7</sub> ± 3.8</td><td></td><td>4 MORI</td><td>07 BELL</td><td>10.6 e<sup>+</sup>e<sup>-</sup> →<br>e<sup>+</sup>e<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>61 ± 9 <sup>+14</sup><sub>- 8</sub></td><td>2584</td><td>5 GARMASH</td><td>05 BELL</td><td>B<sup>+</sup> → K<sup>+</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>64 ± 16</td><td></td><td>6 ANISOVICH</td><td>03 RVUE</td><td></td></tr><tr><td>121 ± 23</td><td></td><td>TIKHOMIROV</td><td>03 SPEC</td><td>40.0 K<sub>S</sub><sup>-</sup>K<sub>S</sub><sup>0</sup>K<sub>S</sub><sup>+</sup>X</td></tr><tr><td>~ 70</td><td></td><td>7 BRAMON</td><td>02 RVUE</td><td>1.02 e<sup>+</sup>e<sup>-</sup> →<br>π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>44 ± 2 ± 2</td><td>848</td><td>8 AITALA</td><td>01A E791</td><td>D<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>+</sup></td></tr><tr><td>201 ± 28</td><td>419</td><td>9 ACHASOV</td><td>00H SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>122 ± 13</td><td>419</td><td>10,11 ACHASOV</td><td>00H SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>56 ± 20</td><td></td><td>12 AKHMETSHIN</td><td>99C CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>65 ± 20</td><td></td><td>BARBERIS</td><td>99 OMEG</td><td>450 pp →<br>p<sub>S</sub>pF K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>80 ± 10</td><td></td><td>BARBERIS</td><td>99B OMEG</td><td>450 pp →<br>p<sub>S</sub>pF π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>80 ± 10</td><td></td><td>BARBERIS</td><td>99C OMEG</td><td>450 pp →<br>p<sub>S</sub>pF π<sup>0</sup>π<sup>0</sup></td></tr><tr><td>48 ± 12 ± 8</td><td></td><td>13 BARBERIS</td><td>99D OMEG</td><td>450 pp → K<sup>+</sup>K<sup>-</sup>,<br>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>65 ± 25</td><td></td><td>BELLAZZINI</td><td>99 GAM4</td><td>450 pp → p<sub>S</sub>pπ<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>71 ± 14</td><td></td><td>14 KAMINSKI</td><td>99 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup>, σσ</td></tr><tr><td>~ 28</td><td></td><td>14 OLLER</td><td>99 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>~ 25</td><td></td><td>OLLER</td><td>99B RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>~ 14</td><td></td><td>14 OLLER</td><td>99C RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup>, ηη</td></tr><tr><td>70 ± 20</td><td></td><td>ALDE</td><td>98 GAM4</td><td></td></tr><tr><td>86 ± 16</td><td></td><td>14 ANISOVICH</td><td>98B RVUE</td><td>Compilation</td></tr><tr><td>54</td><td></td><td>15 LOCHER</td><td>98 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>69 ± 15</td><td></td><td>16 ALDE</td><td>97 GAM2</td><td>450 pp → p<sub>S</sub>pπ<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>38 ± 20</td><td></td><td>17 BERTIN</td><td>97C OBLX</td><td>0.0 p<sub>S</sub>p → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>0</td></tr><tr><td>~ 100</td><td></td><td>18 ISHIDA</td><td>96 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>34</td><td></td><td>TORNQVIST</td><td>96 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup>, Kπ,<br>ηπ</td></tr><tr><td>48 ± 10</td><td>3k</td><td>19 ALDE</td><td>95B GAM2</td><td>38 π<sup>-</sup>p → π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>95 ± 20</td><td>10k</td><td>20 ALDE</td><td>95B GAM2</td><td>38 π<sup>-</sup>p → π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>26 ± 10</td><td></td><td>AMSLER</td><td>95B CBAR</td><td>0.0 p<sub>S</sub>p → 3π<sup>0</sup></td></tr><tr><td>~ 112</td><td></td><td>21 AMSLER</td><td>95D CBAR</td><td>0.0 p<sub>S</sub>p → π<sup>0</sup>π<sup>0</sup>π<sup>0</sup>0,<br>π<sup>0</sup>ηηη, π<sup>0</sup>π<sup>0</sup>η</td></tr><tr><td>80 ± 12</td><td></td><td>22 ANISOVICH</td><td>95 RVUE</td><td></td></tr><tr><td>30</td><td></td><td>JANSSEN</td><td>95 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>74</td><td></td><td>23 BUGG</td><td>94 RVUE</td><td>p<sub>S</sub>p → η2π<sup>0</sup></td></tr><tr><td>29 ± 2</td><td></td><td>24 KAMINSKI</td><td>94 RVUE</td><td>ππ → ππ, K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>46</td><td></td><td>25 ZOU</td><td>94B RVUE</td><td></td></tr><tr><td>48 ± 12</td><td></td><td>26 MORGAN</td><td>93 RVUE</td><td>ππ(K<sup>+</sup>K<sup>-</sup>) →<br>ππ(K<sup>+</sup>K<sup>-</sup>), J/ψ →<br>θππ(K<sup>+</sup>K<sup>-</sup>), D<sub>S</sub> →<br>π(ππ)</td></tr><tr><td>37.4 ± 10.6</td><td></td><td>16 AGUILAR-...</td><td>91 EHS</td><td>400 pp</td></tr><tr><td>72 ± 8</td><td></td><td>27 ARMSTRONG</td><td>91 OMEG</td><td>300 pp → p<sub>S</sub>pππ,<br>p<sub>S</sub>pK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>110 ± 30</td><td></td><td>BREAKSTONE</td><td>90 SFM</td><td>p<sub>S</sub>p → p<sub>S</sub>pπ<sup>+</sup>π<sup>-</sup></td></tr><tr><td>29 ± 13</td><td></td><td>16 ABACHI</td><td>86B HRS</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>X</td></tr><tr><td>120 ± 281 ± 20</td><td></td><td>ETKIN</td><td>82B MPS</td><td>23 π<sup>-</sup>p → n2K<sub>S</sub><sup>0</sup></td></tr><tr><td>28 ± 10</td><td></td><td>27 GIDAL</td><td>81 MRK2</td><td>J/ψ → π<sup>+</sup>π<sup>-</sup>X</td></tr><tr><td>70 to 300</td><td></td><td>28 ACHASOV</td><td>80 RVUE</td><td></td></tr><tr><td>100 ± 80</td><td></td><td>29 AGUILAR-...</td><td>78 HBC</td><td>0.7 p<sub>S</sub>p → K<sub>S</sub><sup>0</sup>K<sub>S</sub><sup>0</sup></td></tr></tbody></table>

<table><tbody><tr><td>30 ± 8</td><td>27 LEEPER</td><td>77</td><td>ASPK</td><td>2–2.4 π<sup>-</sup>p → π<sup>+</sup>π<sup>-</sup>n, K<sup>+</sup>K<sup>-</sup>n</td></tr><tr><td>48 ± 14</td><td>27 BINNIE</td><td>73</td><td>CNTR</td><td>π<sup>-</sup>p → nMM</td></tr><tr><td>32 ± 10</td><td>30 GRAYER</td><td>73</td><td>ASPK</td><td>17 π<sup>-</sup>p → π<sup>+</sup>π<sup>-</sup>n</td></tr><tr><td>30 ± 10</td><td>30 HYAMS</td><td>73</td><td>ASPK</td><td>17 π<sup>-</sup>p → π<sup>+</sup>π<sup>-</sup>n</td></tr><tr><td>54 ± 16</td><td>30 PROTOPOP...</td><td>73</td><td>HBC</td><td>7 π<sup>+</sup>p → π<sup>+</sup>pπ<sup>+</sup>π<sup>-</sup></td></tr></tbody></table>

1 Using a relativistic Breit-Wigner function and taking into account the finite $D_S$ mass.

2 Breit-Wigner $\pi\pi$ width. Using finite width corrections according to FLATTE 76 and ACHASOV 05, and the ratio $g_{f_0 K K}/g_{f_0 \pi\pi} = 0$.

3 Systematic errors not estimated.

4 Breit-Wigner $\pi\pi$ width. Using finite width corrections according to FLATTE 76 and ACHASOV 05, and the ratio $g_{f_0 K K}/g_{f_0 \pi\pi} = 4.21 \pm 0.25 \pm 0.21$ from ABLIKIM 05.

5 Breit-Wigner, solution 1, PWA ambiguous.

6 K-matrix pole from combined analysis of $\pi^-p \to \pi^0\pi^0n, \pi^-p \to K\bar{K}n, \pi^+\pi^- \to \pi^+\pi^-, p\bar{p}p \to \pi^0\pi^0\pi^0, \pi^0\eta\eta, \pi^0\pi^0\eta, \pi^+\pi^-\pi^0, K^+K^-\pi^0, K^0K^0S^0\pi^0, K^+K^0\pi^- \text{ at rest, } p\bar{p}n \to \pi^-\pi^-\pi^+, K^0S^0K^-\pi^0, K^0S^0K^0\pi^- \text{ at rest.}$

7 Using the data of AKHMETSHIN 99C, ACHASOV 00H, and ALOISIO 02D.

8 Breit-Wigner width.

9 Supersedes ACHASOV 98i. Using the model of ACHASOV 89.

10 Supersedes ACHASOV 98i.

11 In the "narrow resonance" approximation.

12 From the combined fit of the photon spectra in the reactions $e^+e^- \to \pi^+\pi^-\gamma, \pi^0\pi^0\gamma$.

13 Supersedes BARBERIS 99 and BARBERIS 99B.

14 T-matrix pole.

15 On sheet II in a 2 pole solution. The other pole is found on sheet III at (1039–93j) MeV.

16 From invariant mass fit.

17 On sheet II in a 2 pole solution. The other pole is found on sheet III at (963-29i) MeV.

18 Reanalysis of data from HYAMS 73, GRAYER 74, SRINIVASAN 75, and ROSSELET 77 using the interfering amplitude method.

19 At high $|t|$.

20 At low $|t|$.

21 On sheet II in a 4-pole solution, the other poles are found on sheet III at (953–55j) MeV and on sheet IV at (938–35j) MeV.

22 Combined fit of ALDE 95b, ANISOVICH 94.

23 On sheet II in a 2 pole solution. The other pole is found on sheet III at (996–103j) MeV.

24 From sheet II pole position.

25 On sheet II in a 2 pole solution. The other pole is found on sheet III at (797–185j) MeV and can be interpreted as a shadow pole.

26 On sheet II in a 2 pole solution. The other pole is found on sheet III at (978–28j) MeV.

27 From coupled channel analysis.

28 Coupled channel analysis with finite width corrections.

29 From coupled channel fit to the HYAMS 73 and PROTOPOPESCU 73 data. With a simultaneous fit to the $\pi\pi$ phase-shifts, inelasticity and to the $K^0S K^0S$ invariant mass.

30 Included in AGUILAR-BENITEZ 78 fit.

f₀(980) DECAY MODES

<table><thead><tr><th>Mode</th><th>Fraction (Γ<sub>i</sub>/Γ)</th></tr></thead><tbody><tr><td>Γ<sub>1</sub> ππ</td><td>seen</td></tr><tr><td>Γ<sub>2</sub> K<sup>+</sup>K<sup>-</sup></td><td>seen</td></tr><tr><td>Γ<sub>3</sub> γγ</td><td>seen</td></tr><tr><td>Γ<sub>4</sub> e<sup>+</sup>e<sup>-</sup></td><td>seen</td></tr></tbody></table>

f₀(980) PARTIAL WIDTHS

<table><thead><tr><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>0.29 <sup>+0.11</sup><sub>-0.06</sub> OUR AVERAGE</td><td></td><td></td><td></td></tr><tr><td>0.286 ± 0.017 <sup>+0.211</sup><sub>-0.070</sub></td><td>1 UEHARA</td><td>08A BELL</td><td>10.6 e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>0.205 <sup>+0.095</sup><sub>-0.083</sub> <sup>+0.147</sup><sub>-0.117</sub></td><td>2 MORI</td><td>07 BELL</td><td>10.6 e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>0.42 ± 0.06 ± 0.18</td><td>3 OEST</td><td>90 JADE</td><td>e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>• • • We do not use the following data for averages, fits, limits, etc. • • •</td><td></td><td></td><td></td></tr><tr><td>0.32 ± 0.05</td><td>4 DAI</td><td>14A RVUE</td><td>Compilation</td></tr><tr><td>0.16 ± 0.01</td><td>5 MENNESSIER</td><td>11 RVUE</td><td></td></tr><tr><td>0.29 ± 0.21 <sup>+0.02</sup><sub>-0.07</sub></td><td>6 MOUSSALLAM11</td><td>RVUE</td><td>Compilation</td></tr><tr><td>0.42</td><td>7.8 PENNINGTON 08</td><td>RVUE</td><td>Compilation</td></tr><tr><td>0.10</td><td>8.9 PENNINGTON 08</td><td>RVUE</td><td>Compilation</td></tr><tr><td>0.28 <sup>+0.09</sup><sub>-0.13</sub></td><td>10 BOGLIONE</td><td>99 RVUE</td><td>γγ → π<sup>+</sup>π<sup>-</sup>, π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>0.29 ± 0.07 ± 0.12</td><td>11.12 BOYER</td><td>90 MRK2</td><td>e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>0.31 ± 0.14 ± 0.09</td><td>11.12 MARISKE</td><td>90 CBAL</td><td>e<sup>+</sup>e<sup>-</sup> → e<sup>+</sup>e<sup>-</sup>π<sup>0</sup>π<sup>0</sup>0</td></tr><tr><td>0.63 ± 0.14</td><td>13 MORGAN</td><td>90 RVUE</td><td>γγ → π<sup>+</sup>π<sup>-</sup>, π<sup>0</sup>π<sup>0</sup>0</td></tr></tbody></table>

1 Using finite width corrections according to FLATTE 76 and ACHASOV 05, and the ratio $g_{f_0 K K}/g_{f_0 \pi\pi} = 0$.

2 Using finite width corrections according to FLATTE 76 and ACHASOV 05, and the ratio $g_{f_0 K K}/g_{f_0 \pi\pi} = 4.21 \pm 0.25 \pm 0.21$ from ABLIKIM 05.

3 OEST 90 quote systematic errors $\pm 0.08$; we use $\pm 0.18$. Observed 60 events.

4 Using dispersive analysis with phases from GARCIA-MARTIN 11A and BUETTIKER 04 as input.
# Meson Particle Listings

$f_0(980), a_0(980)$

⁵ Uses an analytic K-matrix integral. Compilation.

⁶ Using dispersion integral with phase input from Roy equations and data from MAR-SISKE 90, BOYER 90, BEHREND 92, UEHARA 08A, and MORI 07.

⁷ Solution A (preferred solution based on $\chi^2$-analysis).

⁸ Dispersion theory based amplitude analysis of BOYER 90, MARSISKE 90, BEHREND 92, and MORI 07.

⁹ Solution B (worse than solution A; still acceptable when systematic uncertainties are included).

¹⁰ Supersedes MORGAN 90.

¹¹ From analysis allowing arbitrary background unconstrained by unitarity.

¹² Data included in MORGAN 90, BOGLIONE 99 analyses.

¹³ From amplitude analysis of BOYER 90 and MARSISKE 90, data corresponds to resonance parameters $m = 989$ MeV, $\Gamma = 61$ MeV.

<table><thead><tr><th>Γ(e<sup>+</sup>e<sup>-</sup>)</th><th>CL%</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>&lt;8.4</td><td>90</td><td>VOROBYEV</td><td>88</td><td>ND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup></td></tr></tbody></table>

## f₀(980) BRANCHING RATIOS

<table><thead><tr><th>Γ(ππ)/[Γ(ππ) + Γ(KK)]</th><th>EVENTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>0.52 ± 0.12</td><td>9.9k</td><td>1 AUBERT</td><td>060</td><td>BABR</td><td>B<sup>±</sup> → K<sup>±</sup>π<sup>±</sup>π<sup>±</sup></td></tr><tr><td>0.75 <sup>+0.11</sup><sub>-0.13</sub></td><td></td><td>2 ABLIKIM</td><td>05Q</td><td>BES2</td><td>χ<sub>0</sub><sup>0</sup> → 2π<sup>+</sup>2π<sup>-</sup>, π<sup>+</sup>π<sup>-</sup> K<sup>+</sup> K<sup>-</sup></td></tr><tr><td>0.84 ± 0.02</td><td></td><td>3 ANISOVICH</td><td>02d</td><td>SPEC</td><td>Combined fit</td></tr><tr><td>~ 0.68</td><td></td><td>OLLER</td><td>99B</td><td>RVUE</td><td>ππ → ππ, K<sup>K</sup></td></tr><tr><td>0.67 ± 0.09</td><td></td><td>4 LOVERRE</td><td>80</td><td>HBC</td><td>4 π<sup>-</sup> p → n2K<sup>S</sup></td></tr><tr><td>0.81 <sup>+0.09</sup><sub>-0.04</sub></td><td></td><td>4 CASON</td><td>78</td><td>STRC</td><td>7 π<sup>-</sup> p → n2K<sup>S</sup></td></tr><tr><td>0.78 ± 0.03</td><td></td><td>4 WETZEL</td><td>76</td><td>OSPK</td><td>8.9 π<sup>-</sup> p → n2K<sup>S</sup></td></tr></tbody></table>

¹ Recalculated by us using $Γ(K^+K^-) / Γ(π^+π^-) = 0.69 \pm 0.32$ from AUBERT 060 and isospin relations.

² Using data from ABLIKIM 046.

³ From a combined K-matrix analysis of Crystal Barrel ($ρ\bar{p} → π^0π^0π^0, π^0ηη, π^0ηη, π^0ηη$), GAMS ($πp → π^0π^0, πηη, πηη, πηη$), and BNL ($πp → K\bar{K}n$) data.

⁴ Measure $ππ$ elasticity assuming two resonances coupled to the $ππ$ and $K\bar{K}$ channels only.

## f₀(980) REFERENCES

<table><tbody><tr><td>DANILKIN</td><td>21</td><td>PR D103 114023</td><td>I. Danilkin, O. Deineka, M. Vanderhaeghen</td><td>(MAINZ)</td></tr><tr><td>SARANTSEV</td><td>21</td><td>PL B816 136227</td><td>A.V. Sarantsev et al.</td><td>(BONN, PNPI)</td></tr><tr><td>ALBRECHT</td><td>20</td><td>EPJ C80 453</td><td>M. Albrecht et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>AAIJ</td><td>19H</td><td>JHEP 1904 063</td><td>R. Aaij et al.</td><td>(LHCb Collab.)</td></tr><tr><td>AOUDE</td><td>18</td><td>PR D98 056021</td><td>R.T. Aoude et al.</td><td></td></tr><tr><td>GARCIA-MAR-</td><td>15P</td><td>PR D92 012007</td><td>M. Ablikim et al.</td><td>(BESIII Collab.)</td></tr><tr><td>DAL</td><td>14A</td><td>PR D90 036004</td><td>L.-Y. Dai, M.R. Pennington</td><td>(CEBAF)</td></tr><tr><td>ABLIKIM</td><td>12E</td><td>PRL 108 182001</td><td>M. Ablikim et al.</td><td>(BESIII Collab.)</td></tr><tr><td>GARCIA-MAR-</td><td>11A</td><td>PR D83 074004</td><td>R. Garcia-Martin et al.</td><td>(MADR, CRAC)</td></tr><tr><td>MENNESSIER</td><td>11</td><td>PR B696 40</td><td>G. Mennessier, S. Narison, X.-G. Wang</td><td></td></tr><tr><td>MOUSSALLAM</td><td>11</td><td>EPJ C71 1814</td><td>B. Moussallam</td><td></td></tr><tr><td>BATLEY</td><td>10C</td><td>EPJ C70 635</td><td>J.R. Batley et al.</td><td>(CERN NA48/2 Collab.)</td></tr><tr><td>MENNESSIER</td><td>10</td><td>PL B688 59</td><td>G. Mennessier, S. Narison, X.-G. Wang</td><td></td></tr><tr><td>ANISOVICH</td><td>09</td><td>IJMP A24 2481</td><td>V.V. Anisovich, A.V. Sarantsev</td><td>(PNPI)</td></tr><tr><td>ECKLUND</td><td>09</td><td>PR D60 052009</td><td>K.M. Ecklund et al.</td><td>(CLEO Collab.)</td></tr><tr><td>BATLEY</td><td>08A</td><td>EPJ C54 411</td><td>J.R. Batley et al.</td><td>(CERN NA48/2 Collab.)</td></tr><tr><td>PENNINGTON</td><td>08</td><td>EPJ C56 1</td><td>M.R. Pennington et al.</td><td></td></tr><tr><td>UEHARA</td><td>08A</td><td>PR D78 052004</td><td>S. Uehara et al.</td><td>(BELLE Collab.)</td></tr><tr><td>AMBROSINO</td><td>07</td><td>EPJ C49 473</td><td>F. Ambrosino et al.</td><td>(KLOE Collab.)</td></tr><tr><td>AUBERT</td><td>07AK</td><td>PR D76 012008</td><td>B. Aubert et al.</td><td>(BABAR Collab.)</td></tr><tr><td>BONVICINI</td><td>07</td><td>PR D76 012001</td><td>G. Bonvicini et al.</td><td>(CLEO Collab.)</td></tr><tr><td>MORI</td><td>07</td><td>PR D75 051101</td><td>T. Mori et al.</td><td>(BELLE Collab.)</td></tr><tr><td>AMBROSINO</td><td>06B</td><td>EPJ B634 148</td><td>F. Ambrosino et al.</td><td>(KLOE Collab.)</td></tr><tr><td>AUBERT</td><td>06O</td><td>PR D74 032003</td><td>B. Aubert et al.</td><td>(BABAR Collab.)</td></tr><tr><td>GARMASH</td><td>06</td><td>PR D76 251803</td><td>A. Garmash et al.</td><td>(BELLE Collab.)</td></tr><tr><td>ABLIKIM</td><td>05</td><td>PR D72 092002</td><td>M. Ablikim et al.</td><td>(BES Collab.)</td></tr><tr><td>ACHASOV</td><td>05Q</td><td>PR D72 091306</td><td>N.N. Achasov, G.N. Shestakov</td><td>(BELLE Collab.)</td></tr><tr><td>GARMASH</td><td>05</td><td>PR D71 092003</td><td>A. Garmash et al.</td><td>(BES Collab.)</td></tr><tr><td>ABLIKIM</td><td>04G</td><td>PR D70 092002</td><td>M. Ablikim et al.</td><td>(BELLE Collab.)</td></tr><tr><td>BUETTIKER</td><td>04A</td><td>EPJ B33 409</td><td>P. Buettiker, S. Descotes-Genon, B. Moussallam</td><td></td></tr><tr><td>PELAEZ</td><td>04A</td><td>MPL A19 2879</td><td>J.R. Pelaez</td><td>(MADU)</td></tr><tr><td>ANISOVICH</td><td>03</td><td>EPJ A16 229</td><td>V.V. Anisovich et al.</td><td></td></tr><tr><td>TIKHOIMIROV</td><td>03</td><td>PAN 66 828</td><td>G.D. Tikhomirov et al.</td><td></td></tr><tr><td>ALOISIO</td><td>02D</td><td>PL B537 21</td><td>A. Aloisio et al.</td><td>(KLOE Collab.)</td></tr><tr><td>ANISOVICH</td><td>02D</td><td>PAN 65 1545</td><td>V.V. Anisovich et al.</td><td></td></tr><tr><td></td><td></td><td>Translated from YAF 66 860.</td><td></td><td></td></tr><tr><td>BRAMON</td><td>02</td><td>EPJ C26 253</td><td>A. Bramon et al.</td><td></td></tr><tr><td>ACHASOV</td><td>01F</td><td>PR D63 094007</td><td>N.N. Achasov, V.V. Gubin</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>AITALA</td><td>01A</td><td>PR B6 765</td><td>E.M. Aitala et al.</td><td>(FNAL E791 Collab.)</td></tr><tr><td>AITALA</td><td>00B</td><td>PRL 86 770</td><td>E.M. Aitala et al.</td><td>(FNAL E791 Collab.)</td></tr><tr><td>ACHASOV</td><td>01H</td><td>PL B485 349</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>99B</td><td>PL B462 371</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>99C</td><td>PL B462 380</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>BARBERIS</td><td>99</td><td>PL B453 305</td><td>V. Barberis et al.</td><td>(Omega Expt.)</td></tr><tr><td>BARBERIS</td><td>99B</td><td>PL B453 316</td><td>D. Barberis et al.</td><td>(Omega Expt.)</td></tr><tr><td>BARBERIS</td><td>99C</td><td>PL B453 325</td><td>D. Barberis et al.</td><td>(Omega Expt.)</td></tr><tr><td>BARBERIS</td><td>99D</td><td>PL B462 462</td><td>D. Barberis et al.</td><td>(Omega Expt.)</td></tr><tr><td>BELLAZZINI</td><td>99</td><td>PL B467 296</td><td>R. Bellazini et al.</td><td></td></tr><tr><td>BOGLIONE</td><td>99</td><td>EPJ C9 11</td><td>M. Bogline, M.R. Pennington</td><td></td></tr><tr><td>KAMINSKI</td><td>99</td><td>EPJ C9 141</td><td>R. Kaminski, L. Lesniah, B. Loiseau</td><td>(CRAC, PARIN)</td></tr><tr><td>OLLER</td><td>99</td><td>PR D60 099906 (errat.)</td><td>J.A. Oller et al.</td><td></td></tr><tr><td>OLLER</td><td>99B</td><td>NP A652 407 (errat.)</td><td>J.A. Oller, E. Oset</td><td></td></tr><tr><td>OLLER</td><td>99C</td><td>PR D60 074023</td><td>J.A. Oller, E. Oset</td><td></td></tr><tr><td>ACHASOV</td><td>98I</td><td>PL B440 442</td><td>M.N. Achasov et al.</td><td></td></tr><tr><td>ACKERSTAFF</td><td>98Q</td><td>EPJ C4 19</td><td>K. Ackerstaff et al.</td><td>(OPAL Collab.)</td></tr><tr><td>ALDE</td><td>98</td><td>EPJ A3 361</td><td>D. Alde et al.</td><td>(GAM4 Collab.)</td></tr><tr><td>Also</td><td></td><td>PAN 62 405</td><td>D. Alde et al.</td><td>(GAMS Collab.)</td></tr><tr><td>ANISOVICH</td><td>98B</td><td>SPU 41 419</td><td>V.V. Anisovich et al.</td><td></td></tr></tbody></table>

<table><tbody><tr><td>LOCHER</td><td>97</td><td>EPJ C4 317</td><td>M.P. Locher et al.</td><td>(PSI)</td></tr><tr><td>ALDE</td><td>98</td><td>PL B397 350</td><td>D.M. Alde et al.</td><td>(GAMS Collab.)</td></tr><tr><td>BERTIN</td><td>97</td><td>PL B408 476</td><td>A. Bertin et al.</td><td>(OBELIX Collab.)</td></tr><tr><td>ISHIDA</td><td>96</td><td>PTP 95 745</td><td>S. Ishida et al.</td><td>(TOKY, MIYA, KEK)</td></tr><tr><td>TORNQVIST</td><td>96</td><td>PRL 76 1575</td><td>N.A. Tornqvist, M. Roos</td><td>(HELS)</td></tr><tr><td>ALDE</td><td>95B</td><td>ZPHY C66 375</td><td>D.M. Alde et al.</td><td>(GAMS Collab.)</td></tr><tr><td>AMSLER</td><td>95B</td><td>PL B342 433</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>AMSLER</td><td>95D</td><td>PL B355 425</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>ANISOVICH</td><td>95</td><td>PL B355 363</td><td>V.V. Anisovich et al.</td><td>(PNPI, SERP)</td></tr><tr><td>JANSSEN</td><td>95</td><td>PR D52 2690</td><td>G. Janssen et al.</td><td>(STON, ADLD, JULI)</td></tr><tr><td>AMSLER</td><td>94D</td><td>PL B333 277</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>ANISOVICH</td><td>94</td><td>PL B323 233</td><td>V.V. Anisovich et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>BUGG</td><td>94</td><td>PR D50 4412</td><td>D.V. Bugg et al.</td><td>(LOQM)</td></tr><tr><td>KAMINSKI</td><td>94</td><td>PR D50 3145</td><td>R. Kaminski, L. Lesniah, J.P. Maillet</td><td>(CRAC+)</td></tr><tr><td>ZOU</td><td>94B</td><td>PR D50 591</td><td>B.S. Zou, D.V. Bugg</td><td>(LOQM)</td></tr><tr><td>MORGAN</td><td>93</td><td>PR D48 1185</td><td>D. Morgan, M.R. Pennington</td><td>(RAL, DURH)</td></tr><tr><td>BEHREND</td><td>92</td><td>ZPHY C56 381</td><td>H.J. Behrend</td><td>(CELLO Collab.)</td></tr><tr><td>AGUILAR</td><td>91</td><td>ZPHY C50 405</td><td>M. Aguilar-Benitez et al.</td><td>(LEBC-EHS Collab.)</td></tr><tr><td>ARMSTRONG</td><td>91</td><td>ZPHY C51 351</td><td>T.A. Armstrong et al.</td><td>(ATHU, BARI, BIRM+)</td></tr><tr><td>BOYER</td><td>90</td><td>PR D42 1350</td><td>J. Boyer et al.</td><td>(Mark II Collab.)</td></tr><tr><td>BREAKSTONE</td><td>90</td><td>ZPHY C48 569</td><td>A.M. Breakstone et al.</td><td>(ISU, BGNA, CERN+)</td></tr><tr><td>MARSISKE</td><td>90</td><td>PR D41 3324</td><td>H. Marsiske et al.</td><td>(Crystal Ball Collab.)</td></tr><tr><td>MORGAN</td><td>90</td><td>ZPHY C48 623</td><td>D. Morgan, M.R. Pennington</td><td>(RAL, DURH)</td></tr><tr><td>OEST</td><td>90</td><td>PL C47 343</td><td>T. Oest et al.</td><td>(JADE Collab.)</td></tr><tr><td>ACHASOV</td><td>89</td><td>NP B315 465</td><td>N.N. Achasov, V.N. Ivanchenko</td><td>(DM2 Collab.)</td></tr><tr><td>AUGUSTIN</td><td>89</td><td>NP B320 1</td><td>J.E. Augustin, G. Cosme</td><td>(NOVO)</td></tr><tr><td>VOROBYEV</td><td>88</td><td>SJNP 48 273</td><td>P.V. Vorobiev et al.</td><td></td></tr><tr><td></td><td></td><td>Translated from YAF 48</td><td>436</td><td></td></tr><tr><td>ABACI</td><td>86B</td><td>PRL 57 1990</td><td>S. Abachi et al.</td><td>(PURD, ANL, IND, MICH+)</td></tr><tr><td>LONGACRE</td><td>86</td><td>PL B174 223</td><td>R.S. Longacre et al.</td><td>(BRN, BRAN, CUNY+)</td></tr><tr><td>BINON</td><td>84C</td><td>NC 80A 363</td><td>F.G. Binon et al.</td><td>(BELG, LAPP, SERP+)</td></tr><tr><td>BINON</td><td>83</td><td>NC 78A 313</td><td>F.G. Binon et al.</td><td>(BELG, LAPP, SERP+)</td></tr><tr><td>ETKIN</td><td>82B</td><td>PL D25 1786</td><td>A. Etkin et al.</td><td>(BNL, CUNY, TUFTS, VAND)</td></tr><tr><td>GIDAL</td><td>81</td><td>PL 107B 153</td><td>G. Gidal et al.</td><td>(SLAC, LBL)</td></tr><tr><td>ACHASOV</td><td>80</td><td>SJNP 32 566</td><td>N.N. Achasov, S.A. Devyanin, G.N. Shestakov</td><td>(NOVM)</td></tr><tr><td></td><td></td><td>Translated from YAF 32 1098.</td><td></td><td></td></tr><tr><td>COHEN</td><td>80</td><td>PR D22 2595</td><td>D. Cohen et al.</td><td>(ANL) UP</td></tr><tr><td>LOVERRE</td><td>80</td><td>ZPHY C6 187</td><td>P.F. Loverre et al.</td><td>(CERN, CDEF, MADR+) UP</td></tr><tr><td>AGUILAR</td><td>78</td><td>NP B140 73</td><td>M. Aguilar-Benitez et al.</td><td>(MADR, BOMB+)</td></tr><tr><td>CASON</td><td>78</td><td>PR 41 271</td><td>N.M. Cason et al.</td><td>(NDAM, ANL)</td></tr><tr><td>LEEPER</td><td>77</td><td>PR D16 2054</td><td>R.J. Leeper et al.</td><td>(ISU)</td></tr><tr><td>ROSSELET</td><td>77</td><td>PR D15 574</td><td>L. Rosselet et al.</td><td>(GEVA, SACL)</td></tr><tr><td>FLATE</td><td>76</td><td>PL 63B 224</td><td>S.M. Flate</td><td>(CERN)</td></tr><tr><td>WETZEL</td><td>76</td><td>NP B115 208</td><td>W. Wetzel et al.</td><td>(ETH, CERN, LOIC)</td></tr><tr><td>HYAMS</td><td>75</td><td>NP 100 205</td><td>B.D. Hyams et al.</td><td>(CERN, MPIM)</td></tr><tr><td>SRINIVASAN</td><td>75</td><td>PR D12 681</td><td>V. Srinivasan et al.</td><td>(NDAM, ANL)</td></tr><tr><td>ESTABROOKS</td><td>74</td><td>NP B79 301</td><td>P.G. Estabrooks, A.D. Martin</td><td>(DURH)</td></tr><tr><td>GRAYER</td><td>74</td><td>NP B75 189</td><td>G. Grayer et al.</td><td>(CERN, MPIM)</td></tr><tr><td>BINNIE</td><td>73</td><td>PR 31 1534</td><td>D.M. Binnie et al.</td><td>(LOIC, SHMP)</td></tr><tr><td>GRAYER</td><td>73</td><td>Tallahassee</td><td>G. Grayer et al.</td><td>(CERN, MPIM)</td></tr><tr><td>HYAMS</td><td>73</td><td>NP B64 134</td><td>B.D. Hyams et al.</td><td>(CERN, MPIM)</td></tr><tr><td>PROTOPOP...</td><td>73</td><td>PR D7 1279</td><td>S.D. Protopopescu et al.</td><td>(LBL)</td></tr></tbody></table>

$$a_0(980)$$

$$l^G(J^PC) = 1-(0^{++})$$

See the related review(s):

Scalar Mesons below 1 GeV

## a₀(980) T-MATRIX POLE $\sqrt{s}$

Note that $Γ = -2 \Im(\sqrt{s})$.

**VALUE (MeV)** **DOCUMENT ID** **TECN** **COMMENT**

(970-1020) - i (30-70) OUR ESTIMATE (see Fig. 64.2 in the review)

$$1 \text{ ALBRECHT} \quad 20 \quad \text{CBAR} \quad 0.9 \bar{p}p \rightarrow \pi^0 \eta \eta, \\ \qquad -i(63.5 \pm 2.9)$$

$$1000.7 \pm 12.9 \\ -0.7 \\ -i(36.6 \pm 12.7) \\ -2.6$$

$$989 \pm 5 \rightarrow i(40 \pm 5) \quad 08A \quad \text{RVUE} \quad \bar{p}p \text{ annihilation data}$$

$$1117 \pm 24 \rightarrow i(12^+ \pm 43, \quad 12^- \pm 12) \quad 04A \quad \text{RVUE} \quad \pi\pi \rightarrow \pi\pi, \pi K \rightarrow \pi K$$

$$982 \pm 3 \rightarrow i(46 \pm 4) \quad 98 \quad \text{CBAR} \quad 0.0 \bar{p}p \rightarrow K^0 L^0 K^+ \pi^-$$

¹ Pole mass on sheet closest to the central axis - the more remote pole is extracted at $(1004.1 \pm 1.5 \pm 6.5) \rightarrow i(48.6 \pm 1.2 \pm 3.4)$ MeV.

² T-matrix pole on sheet II.

³ T-matrix pole on sheet II. Parameterizes couplings to $K\bar{K}$, $\pi\eta$, and $\pi\eta'$. Uses AM-SLER 94d and ABELE 98.

⁴ Reanalysis of data from LINGLIN 73, ESTABROOKS 78, and ASTON 88 in the unitarized ChPT model.

⁵ T-matrix pole on sheet II; the pole on sheet III is at $(1006 - i 49)$ MeV.

## a₀(980) MASS

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>982.5 ± 1.6 ± 1.1</td><td>16.9k</td><td>1 AMBROSINO</td><td>09F</td><td>KLOE</td></tr><tr><td>986 ± 4</td><td></td><td>ANISOVICH</td><td>09</td><td>RVUE</td></tr><tr><td>982.3 ± 0.6 ± 3.1</td><td>2 UEHARA</td><td>09A</td><td>BELL</td><td>γγ → πη</td></tr><tr><td>985 ± 4 ± 6</td><td>318</td><td>ACHARD</td><td>02B</td><td>L3</td></tr><tr><td>995 ± 52</td><td>36</td><td>3 ACHASOV</td><td>00F</td><td>SND</td></tr><tr><td>994 ± 33</td><td>36</td><td>4 ACHASOV</td><td>00F</td><td>SND</td></tr><tr><td>975 ± 7</td><td></td><td>BARBERIS</td><td>00H</td><td></td></tr></tbody></table>
# Meson Particle Listings

a₀(980), φ(1020)

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>0.138 ± 0.001 ± 0.035</td><td>4 ALBRECHT</td><td>20</td><td>CBAR</td><td>0.9 <span style="text-decoration: overline;">p</span> → π<sup>0</sup>π<sup>0</sup>η<sub>1</sub>,<br/>π<sup>0</sup>η<sub>1</sub>, π<sup>0</sup>K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1.20 ± 0.15</td><td>5 ANISOVICH</td><td>09</td><td>RVUE</td><td>0.0 <span style="text-decoration: overline;">p</span> → πN</td></tr><tr><td>1.05 ± 0.07 ± 0.05</td><td>6 BUGG</td><td>08A</td><td>RVUE</td><td>0 <span style="text-decoration: overline;">p</span> → π<sup>0</sup>π<sup>0</sup>η</td></tr><tr><td>0.57 ± 0.16</td><td>7 BARGIOTTI</td><td>03</td><td>OBLX</td><td>ππ → ηπ, K<span style="text-decoration: overline;">K</span></td></tr><tr><td>~ 0.60</td><td>OLLER</td><td>99B</td><td>RVUE</td><td></td></tr><tr><td>0.7 ± 0.03</td><td>3 CORDEN</td><td>78</td><td>OMEG</td><td>12-15 π<sup>-</sup> p → ηη2π</td></tr><tr><td>0.25 ± 0.08</td><td>3 DEFOIX</td><td>72</td><td>HBC</td><td>0.7 <span style="text-decoration: overline;">p</span> → 7π</td></tr></tbody></table>

¹ Using $D_S^+ \to a_0(980) + \pi^0$ from ABLIKIM 19BE.

² Using $\pi^0\pi^0\eta$ from AMSLER 94D.

³ From the decay of $\tau_1$ (1285).

⁴ Residues from T-matrix pole with 2 poles, 2 channels. Solution on adjacent sheet 0.149 ± 0.001 ± 0.039.

⁵ This is a ratio of couplings.

⁶ A ratio of couplings, using AMSLER 94D and ABELE 98. Supersedes BUGG 94.

⁷ Coupled channel analysis of $\pi^+\pi^-\pi^0, K^+K^-\pi^0$, and $K^\pm K_S^+\pi^+$.

## Γ(ηπ)/Γtotal

<table><thead><tr><th>VALUE</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>seen</td><td>116k</td><td>1 CHEN</td><td>20A</td><td>BELL</td></tr></tbody></table>

## Γ<sub>3</sub>/Γ

¹ From an amplitude analysis of the $D^0 \to K^-\pi^+\eta$ decay in a three-channel Flattie model with a 10.1 σ significance. Earlier observed by ABLIKIM 17k in the $\chi_{c1} \to \eta\pi^+\pi^-$ decay with a 8.9 σ significance.

## Γ(ρπ)/Γ(ηπ)

<table><thead><tr><th>VALUE</th><th>CL%</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td colspan="6">ρπ forbidden.</td></tr><tr><td>&lt;0.25</td><td>70</td><td>1 AMMAR</td><td>70</td><td>HBC</td><td>± 4.1,5.5 K<sup>-</sup> p → Λη2π</td></tr></tbody></table>

¹ Not clear if they really observed the $a_0(980)$ 3 standard deviations.

## a₀(980) REFERENCES

<table><tbody><tr><td>ABLIKIM</td><td>22AH</td><td>PRL 129 182001</td><td>M. Ablikim et al.</td><td>(BESIII Collab.)</td></tr><tr><td>ALBRECHT</td><td>20</td><td>EPJ C80 453</td><td>M. Albrecht et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>CHEN</td><td>20A</td><td>PRL D102 012002</td><td>Y.-Q. Chen et al.</td><td>(BELLE Collab.)</td></tr><tr><td>LU</td><td>20</td><td>EPJ C80 436</td><td>J. Lu, B. Moussallam</td><td></td></tr><tr><td>AAIJ</td><td>19H</td><td>JHEP 1904 063</td><td>R. Aaij et al.</td><td>(LHCb Collab.)</td></tr><tr><td>ABLIKIM</td><td>19BE</td><td>PRL 123 112001</td><td>M. Ablikim et al.</td><td>(BESIII Collab.)</td></tr><tr><td>AOUDE</td><td>18</td><td>PRL D98 056021</td><td>R.T. Aoude et al.</td><td></td></tr><tr><td>ABLIKIM</td><td>17K</td><td>PRL D95 032002</td><td>M. Ablikim et al.</td><td>(BESIII Collab.)</td></tr><tr><td>AAIJ</td><td>16N</td><td>PRL D93 052018</td><td>R. Aaij et al.</td><td>(LHCb Collab.)</td></tr><tr><td>AMBROSINO</td><td>09F</td><td>PL B681 5</td><td>F. Ambrosino et al.</td><td>(KLOE Collab.)</td></tr><tr><td>ANISOVICH</td><td>09F</td><td>IJMP A24 2481</td><td>V.V. Anisovich, A.V. Sarantsev</td><td>(PNPI)</td></tr><tr><td>UEHARA</td><td>09A</td><td>PRL D80 032001</td><td>S. Uehara et al.</td><td>(BELLE Collab.)</td></tr><tr><td>BUGG</td><td>08A</td><td>PRL D78 074023</td><td>D.V. Bugg</td><td>(LOQM)</td></tr><tr><td>PELAEZ</td><td>04A</td><td>PRL A19 2879</td><td>J.R. Pelaez</td><td>(MADU)</td></tr><tr><td>ACHASOV</td><td>03B</td><td>PRL D68 014006</td><td>N.N. Achasov, A.V. Kiselev</td><td></td></tr><tr><td>BARGIOTTI</td><td>03</td><td>PRL C26 371</td><td>M. Bargiotti et al.</td><td>(OBELIX Collab.)</td></tr><tr><td>ACHARD</td><td>02B</td><td>PL B526 269</td><td>P. Achard et al.</td><td>(L3 Collab.)</td></tr><tr><td>ACHASOV</td><td>00F</td><td>PL B479 53</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>BARBERIS</td><td>00H</td><td>PL B488 225</td><td>D. Barberis et al.</td><td>(WA 102 Collab.)</td></tr><tr><td>OLLER</td><td>99</td><td>PRL D60 099906 (errat.)</td><td>J.A. Oller et al.</td><td></td></tr><tr><td>OLLER</td><td>99B</td><td>NP A652 407 (errat.)</td><td>J.A. Oller, E. Oset</td><td></td></tr><tr><td>OLLER</td><td>99C</td><td>PRL D60 074023</td><td>J.A. Oller, E. Oset</td><td></td></tr><tr><td>TEIGE</td><td>99</td><td>PRL D59 012000</td><td>S. Teige et al.</td><td>(BNL E852 Collab.)</td></tr><tr><td>ABELE</td><td>98</td><td>PRL D57 3860</td><td>A. Barrie et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>ACHASOV</td><td>98B</td><td>PL B438 441</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>AMSLER</td><td>98</td><td>RMP 70 1293</td><td>C. Amsler</td><td></td></tr><tr><td>ANISOVICH</td><td>98B</td><td>SPU 41 419</td><td>V.V. Anisovich et al.</td><td></td></tr><tr><td>BARBERIS</td><td>98C</td><td>PL B440 225</td><td>D. Barberis et al.</td><td>(WA 102 Collab.)</td></tr><tr><td>TERTIN</td><td>98B</td><td>PL B434 180</td><td>A. Bertin et al.</td><td>(OBELIX Collab.)</td></tr><tr><td>BORNQVIST</td><td>96</td><td>PRL 76 1575</td><td>N.A. Tornqvist, M. Roos</td><td>(HELS)</td></tr><tr><td>JANSSEN</td><td>95</td><td>PRL D52 2690</td><td>G. Janssen et al.</td><td>(STON, ADLD, JULI)</td></tr><tr><td>AMSLER</td><td>94C</td><td>PL B327 425</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>AMSLER</td><td>94D</td><td>PL B333 277</td><td>C. Amsler et al.</td><td>(LQQM)</td></tr><tr><td>BUGG</td><td>94</td><td>PRL D50 4412</td><td>D.V. Bugg et al.</td><td></td></tr><tr><td>AMSLER</td><td>92</td><td>PL B291 347</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>ARMSTRONG</td><td>91B</td><td>ZPHY C52 389</td><td>T.A. Armstrong et al.</td><td>(ATHU, BARI, BIRM+)</td></tr><tr><td>OEST</td><td>90</td><td>ZPHY C47 343</td><td>T. Oest et al.</td><td>(JADE Collab.)</td></tr><tr><td>ACHASOV</td><td>89</td><td>NP B315 465</td><td>N.N. Achasov, V.N. Ivanchenko</td><td></td></tr><tr><td>ASTON</td><td>88</td><td>NP B296 493</td><td>D. Aston et al.</td><td>(SLAC, NAGO, CINC, INUS)</td></tr><tr><td>VOROBEYV</td><td>88</td><td>SJPN 48 273</td><td>P.V. Vorobiev et al.</td><td>(NOVO)</td></tr><tr><td>ANTREASYAN</td><td>86</td><td>PRL D33 1847</td><td>D. Antreasyan et al.</td><td>(Crystal Ball Collab.)</td></tr><tr><td>ATKINSON</td><td>84E</td><td>NP 138B 459</td><td>M. Akinson et al.</td><td>(BONN, CERN, GLAS+)</td></tr><tr><td>EVANGELIS...</td><td>81</td><td>NP B178 197</td><td>C. Evangelista et al.</td><td>(BARI, BONN, CERN+)</td></tr><tr><td>DEBILY</td><td>80</td><td>NP B176 1</td><td>L. de Billy et al.</td><td>(CURIN, LAUS, NEUC+)</td></tr><tr><td>GURTU</td><td>79</td><td>NP B151 181</td><td>A. Gurtu et al.</td><td>(CERN, ZEEM, NJJM, OXF)</td></tr><tr><td>CONFORTO</td><td>78</td><td>LNC 23 419</td><td>B. Conforto et al.</td><td>(RHEL, TNT0, CHIC+)</td></tr><tr><td>CORDEN</td><td>78</td><td>NP B144 253</td><td>M.J. Corden et al.</td><td>(BIRM, RHEL, TELA+)</td></tr><tr><td>ESTABROOKS</td><td>78</td><td>NP B133 490</td><td>P. Estabrooks et al.</td><td>(MCGI, CARL, DURH+)</td></tr><tr><td>GRASSLER</td><td>77</td><td>NP B121 189</td><td>H. Grassler et al.</td><td>(AACH3, BERL, BONN+)</td></tr><tr><td>JAFFE</td><td>77</td><td>PRL D15 267,281</td><td>R. Jaffe</td><td>(MIT)</td></tr><tr><td>FLATTE</td><td>76</td><td>PL 63B 224</td><td>S.M. Flatte</td><td>(CERN, AMST, NJUM) JP</td></tr><tr><td>GAY</td><td>76B</td><td>PL 63B 220</td><td>J.B. Gay et al.</td><td>(OXF)</td></tr><tr><td>WELLS</td><td>75</td><td>NP B101 333</td><td>J. Wells et al.</td><td>(CERN)</td></tr><tr><td>LINGLIN</td><td>73</td><td>NP B55 408</td><td>D. Linglin</td><td>(CERN)</td></tr><tr><td>DEFOIX</td><td>72</td><td>NP B44 125</td><td>C. Defoix et al.</td><td>(CDEF, CERN)</td></tr><tr><td>AMMAR</td><td>70</td><td>PRL D2 430</td><td>R. Ammar et al.</td><td>(KANS, NWES, ANL, WISC)</td></tr><tr><td>BARNES</td><td>69C</td><td>PRL 23 610</td><td>V.E. Barnes et al.</td><td>(BNL, SYRA)</td></tr><tr><td>CAMPBELL</td><td>69</td><td>PRL 22 1204</td><td>J.H. Campbell et al.</td><td>(PURD)</td></tr><tr><td>MILLER</td><td>69B</td><td>PRL 29B 255</td><td>D.H. Miller et al.</td><td>(PURD)</td></tr><tr><td>Also</td><td></td><td></td><td>W.L. Yen et al.</td><td>(PURD)</td></tr><tr><td>AMMAR</td><td>68</td><td>PRL 21 1832</td><td>R. Ammar et al.</td><td>(NWES, ANL)</td></tr><tr><td>ASTIER</td><td>67</td><td>PL 25B 294</td><td>A. Astier et al.</td><td>(CDEF, CERN, IRAD)</td></tr><tr><td colspan="5">Includes data of BARLOW 67, CONFORTO 67, and ARMENTEROS 65.</td></tr><tr><td>BARLOW</td><td>67</td><td>NC 50A 701</td><td>J. Barlow et al.</td><td>(CERN, CDEF, IRAD, LIVP)</td></tr><tr><td>CONFORTO</td><td>67</td><td>NP B3 469</td><td>G. Conforto et al.</td><td>(CERN, CDEF, IPNP+)</td></tr><tr><td>ARMENTEROS</td><td>65</td><td>PL 17 344</td><td>R. Armenteros et al.</td><td>(CERN, CDEF)</td></tr><tr><td>ROSENFELD</td><td>65</td><td>Oxford Conf. 58</td><td>A.H. Rosenfeld</td><td>(LRL)</td></tr></tbody></table>

$\phi(1020)$

$I^G(JPC) = 0^{-1(-)}$

## $\phi(1020)$ MASS

<table><thead><tr><th>VALUE (MeV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>1019.461 ± 0.016</td><td>OUR AVERAGE</td><td>1</</td><td>KOZYREV</td><td>18 CMD3 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>,<br/>K<sub>S</sub><sup>0</sup>K<sub>L</sub><sup>0</sup></td></tr><tr><td>1019.462 ± 0.042 ± 0.056</td><td>28k</td><td>2</td><td>LEES</td><td>14H BABR e<sup>+</sup>e<sup>-</sup> → K<sub>S</sub><sup>0</sup>K<sub>L</sub><sup>0</sup>γ</td></tr><tr><td>1019.51 ± 0.02 ± 0.05</td><td>13Q</td><td>3</td><td>LEES</td><td>AKHMETSHIN 06 CMD2 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>0</sup>π<sup>0</sup></td></tr><tr><td>1019.30 ± 0.02 ± 0.10</td><td>105k</td><td>4</td><td>AKHMETSHIN 05</td><td>AKHMETSHIN 05 CMD2 e<sup>+</sup>e<sup>-</sup> → ηγ</td></tr><tr><td>1019.52 ± 0.05 ± 0.05</td><td>17k</td><td>5</td><td>AKHMETSHIN 04</td><td>AKHMETSHIN 04 CMD2 e<sup>+</sup>e<sup>-</sup> → K<sub>S</sub><sup>0</sup>K<sub>S</sub><sup>0</sup></td></tr><tr><td>1019.483 ± 0.011 ± 0.025</td><td>272k</td><td>6</td><td>ACHASOV</td><td>01E SND e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>,<br/>K<sub>S</sub><sup>0</sup>K<sub>L</sub><sup>0</sup>, π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>1019.42 ± 0.05</td><td>1900k</td><td>7</td><td>AKHMETSHIN 08</td><td>AKHMETSHIN 08 CMD2 e<sup>+</sup>e<sup>-</sup> → ηγ</td></tr><tr><td>1019.40 ± 0.04 ± 0.05</td><td>23k</td><td>8</td><td>ACHASOV</td><td>01B CMD2 e<sup>+</sup>e<sup>-</sup> → ηγ</td></tr><tr><td>1019.36 ± 0.12</td><td>200k</td><td>9</td><td>ACHASOV</td><td>00B SND e<sup>+</sup>e<sup>-</sup> → ηγ</td></tr><tr><td>1019.38 ± 0.07 ± 0.08</td><td>2200</td><td>10</td><td>AKHMETSHIN 99F</td><td>AKHMETSHIN 99F CMD2 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup> ≥ 2γ</td></tr><tr><td>1019.51 ± 0.07 ± 0.10</td><td>11169</td><td>11</td><td>AKHMETSHIN 98</td><td>AKHMETSHIN 98 CMD2 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>1019.5 ± 0.4</td><td>1</td><td>12</td><td>BARBERIS</td><td>98 OMEG 450 p p → pp2K<sup>+</sup>2K<sup>-</sup></td></tr><tr><td>1019.42 ± 0.06</td><td>55600</td><td>13</td><td>AKHMETSHIN 95</td><td>AKHMETSHIN 95 CMD2 e<sup>+</sup>e<sup>-</sup> → hadrons</td></tr><tr><td>1019.7 ± 0.3</td><td>2012</td><td>14</td><td>DAVENPORT</td><td>MPSF 400 pA → 4KX</td></tr><tr><td>1019.7 ± 0.1 ± 0.1</td><td>5079</td><td>15</td><td>ALBRECHT</td><td>85D ARG 10 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>X</td></tr><tr><td>1019.3 ± 0.1</td><td>1500</td><td>16</td><td>ARENTON</td><td>82 AEMS 11.8 polar. p p → KK</td></tr><tr><td>1019.67 ± 0.17</td><td>25080</td><td>17</td><td>8 PELLINEN</td><td>82 RVUE</td></tr><tr><td>1019.52 ± 0.13</td><td>3681</td><td>18</td><td>BUKIN</td><td>78C OLYA e<sup>+</sup>e<sup>-</sup> → hadrons</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>1018.4 ± 0.5 ± 0.1</td><td>9 ALBRECHT</td><td>20</td><td>CBAR 0.9 p p → K<sup>+</sup>K<sup>-</sup>π<sup>0</sup></td></tr><tr><td>1019.21 ± 0.04 ± 0.03</td><td>10 HOID</td><td>20</td><td>RVUE e<sup>+</sup>e<sup>-</sup> → π<sub>0</sub>γ</td></tr><tr><td>1019.54 ± 0.10 ± 0.51</td><td>11 AAIJ</td><td>19H</td><td>LHCB p p → D<sup>±</sup>X</td></tr><tr><td>1019.20 ± 0.02 ± 0.01</td><td>12 HOFERICHT... 19</td><td>18</td><td>RVUE e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>1019.469 ± 0.061</td><td>1.7M</td><td>19</td><td>KOZYREV</td><td>18 CMD3 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1019.457 ± 0.061</td><td>610k</td><td>20</td><td>KOZYREV</td><td>16 CMD3 e<sup>+</sup>e<sup>-</sup> → K<sub>S</sub><sup>0</sup>K<sub>L</sub><sup>0</sup></td></tr><tr><td>1019.48 ± 0.01</td><td>13F</td><td>21</td><td>LEES</td><td>13F BABR D<sup>+</sup> → K<sup>+</sup>K<sup>-</sup>π<sup>+</sup></td></tr><tr><td>1019.441 ± 0.008 ± 0.080</td><td>542k</td><td>22</td><td>13 AKHMETSHIN 08</td><td>13 AKHMETSHIN 08 CMD2 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1019.63 ± 0.07</td><td>12540</td><td>23</td><td>14 AUBERT, B</td><td>05J BABR D<sup>0</sup> → K<sup>0</sup>R<sup>0</sup>K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1019.8 ± 0.7</td><td>1</td><td>24</td><td>ARMSTRONG</td><td>86 OMEG 85 π<sup>+</sup>p p → π<sup>+</sup>/p4Kp</td></tr><tr><td>1020.1 ± 0.11</td><td>5526</td><td>25</td><td>14 ATKINSON</td><td>86 OMEG 20-70 γp</td></tr><tr><td>1019.7 ± 1.0</td><td>1</td><td>26</td><td>BEBEK</td><td>86 CLEO e<sup>+</sup>e<sup>-</sup> → γ(4S)</td></tr><tr><td>1019.411 ± 0.008</td><td>642k</td><td>27</td><td>15 DIJKSTRA</td><td>86 SPEC 100-200 π<sup>+</sup>, p, p, K<sup>+</sup>, on Be</td></tr><tr><td>1020.9 ± 0.2</td><td>1</td><td>28</td><td>14 FRAME</td><td>86 OMEG 13 K<sup>+</sup>p → φK<sup>+</sup>p</td></tr><tr><td>1021.0 ± 0.2</td><td>1</td><td>29</td><td>14 ARMSTRONG 83B</td><td>14 ARMSTRONG 83B OMEG 18.5 K<sup>-</sup>p → K<sup>-</sup>K<sup>+</sup>Λ</td></tr><tr><td>1020.0 ± 0.5</td><td>1</td><td>30</td><td>14 ARMSTRONG 83B</td><td>14 ARMSTRONG 83B OMEG 18.5 K<sup>-</sup>p → K<sup>-</sup>K<sup>+</sup>Λ</td></tr><tr><td>1019.7 ± 0.3</td><td>1</td><td>31</td><td>14 BARATE</td><td>83 GOLI 190 π<sup>-</sup> Be → 2μX</td></tr><tr><td>1019.8 ± 0.2 ± 0.5</td><td>766</td><td>32</td><td>IVANOV</td><td>81 OLYA 1-1.4 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1019.4 ± 0.5</td><td>337</td><td>33</td><td>COOPER</td><td>78B HBC 0.7-0.8 p p → K<sub>S</sub><sup>0</sup>K<sub>L</sub><sup>0</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1020 ± 1</td><td>383</td><td>34</td><td>14 BALDI</td><td>77 CNTR 10 π<sup>-</sup> p → π<sup>-</sup>φp</td></tr><tr><td>1018.9 ± 0.6</td><td>800</td><td>35</td><td>COHEN</td><td>77 ASPK 6 π<sup>±</sup> N → K<sup>+</sup>K<sup>-</sup>N</td></tr><tr><td>1019.7 ± 0.5</td><td>454</td><td>36</td><td>KALBFLEISCH</td><td>76 HBC 2.18 K<sup>-</sup>p → ΛK<sup>-</sup>K<sup>-</sup></td></tr><tr><td>1019.4 ± 0.8</td><td>984</td><td>37</td><td>BESCH</td><td>74 CNTR 2 γp → pK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1020.3 ± 0.4</td><td>100</td><td>38</td><td>BALLAM</td><td>73B HBC 2.8-9.3 γp</td></tr><tr><td>1019.4 ± 0.7</td><td>100</td><td>39</td><td>BINNIE</td><td>73B CNTR π<sup>-</sup> p → φp</td></tr><tr><td>1019.6 ± 0.5</td><td>120</td><td>40</td><td>16 AGUILAR....</td><td>72B HBC 3.9,4.6 K<sup>-</sup>p → ΛK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1019.9 ± 0.5</td><td>100</td><td>41</td><td>16 AGUILAR....</td><td>72B HBC 3.9,4.6 K<sup>-</sup>p → K<sup>-</sup>pK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>1020.4 ± 0.5</td><td>131</td><td>42</td><td>COLLEY</td><td>72 HBC 10 K<sup>+</sup>p → K<sup>+</sup>pφ</td></tr><tr><td>1019.9 ± 0.3</td><td>410</td><td>43</td><td>STOTTLE...</td><td>71 HBC 2.9 K<sup>-</sup>p → Σ/ΛK<sup>-</sup></td></tr></tbody></table>

¹ Average of KOZYREV 16 and KOZYREV 18 values taking into account the correlated uncertainties. Supersedes individual KOZYREV 16 and KOZYREV 18 results.

² Using a vector meson dominance model with contribution from $\phi(1020)$ and higher mass excitations of $\rho(770)$, $\omega(782)$, and $\phi(1020)$.

³ Using a phenomenological model based on KHUN 90 with a sum of Breit-Wigner resonances for $\rho(770)$, $\omega(782)$, $\phi(1020)$ and their higher mass excitations.

⁴ Update of AKHMETSHIN 99D

⁵ From the combined fit assuming that the total $\phi(1020)$ production cross section is saturated by those of $K^+K^-$, $K_S K_L$, $\pi^+\pi^-\pi^0$, and $\eta\gamma$ decays modes and using ACHASOV 00b for the $\eta\gamma$ decay mode.

⁶ Using a total width of 4.43 ± 0.05 MeV. Systematic uncertainty included.

⁷ Using a total width of 4.43 ± 0.05 MeV.
⁸ PELLINEN 82 review includes AKERLOF 77, DAUM 81, BALDI 77, AYRES 74, DE-GROTT 74.

⁹ Width fixed at 4.2 MeV.

¹⁰ The values were extracted from a dispersively improved Breit-Wigner parameterization and do not include vacuum polarization. Inclusion of vacuum polarization gives 1019.457 ± 0.020 MeV.

¹¹ From the $D^{+} \to K^{+}K^{+}K^{-}$ Dalitz plot fit with the Triple-M amplitude in the multi-meson model of AOUBE 18.

¹² The values were extracted from a dispersively improved Breit-Wigner parameterization and do not include vacuum polarization.

¹³ Strongly correlated with AKHMETSHIN 04.

¹⁴ Systematic errors not evaluated.

¹⁵ Weighted and scaled average of 12 measurements of DIJKSTRA 86.

¹⁶ Mass errors enlarged by us to $\Gamma/\sqrt{N}$; see the note with the $K^*(892)$ mass.

## $\phi(1020)$ WIDTH

<table><thead><tr><th>VALUE (MeV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td colspan="5"><strong>4.249 ± 0.013 OUR AVERAGE</strong></td></tr><tr><td>4.245 ± 0.013</td><td>2.3M</td><td>1 KOZYREV</td><td>18</td><td>CMD3 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>,<br>K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>L</sub></td></tr><tr><td>4.205 ± 0.103 ± 0.067</td><td>28k</td><td>2 LEES</td><td>14H</td><td>BABR e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>L</sub>γ</td></tr><tr><td>4.29 ± 0.04 ± 0.07</td><td></td><td>3 LEES</td><td>13Q</td><td>BABR e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>γ</td></tr><tr><td>4.30 ± 0.06 ± 0.17</td><td>105k</td><td>AKHMETSHIN 06</td><td>18</td><td>CMD2 0.98-1.06 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>4.280 ± 0.033 ± 0.025</td><td>272k</td><td>4 AKHMETSHIN 04</td><td>18</td><td>CMD2 e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub></td></tr><tr><td>4.21 ± 0.04</td><td>1900k</td><td>5 ACHASOV</td><td>01E</td><td>SND e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>,<br>K<sub>S</sub>K<sub>L</sub>, π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>4.44 ± 0.09</td><td>55600</td><td>AKHMETSHIN 95</td><td>18</td><td>CMD2 e<sup>+</sup>e<sup>-</sup> → hadrons</td></tr><tr><td>4.5 ± 0.7</td><td>1500</td><td>ARENTON</td><td>82</td><td>AEMS 11.8 polar. pp → K K</td></tr><tr><td>4.2 ± 0.6</td><td>766</td><td>6 IVANOV</td><td>81</td><td>OYA 1-1.4 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>4.3 ± 0.6</td><td></td><td>6 CORDIER</td><td>80</td><td>DM1 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>4.36 ± 0.29</td><td>3681</td><td>6 BUKIN</td><td>78C</td><td>OYA e<sup>+</sup>e<sup>-</sup> → hadrons</td></tr><tr><td>4.4 ± 0.6</td><td>984</td><td>6 BESCH</td><td>74</td><td>CNTR 2 γp → pK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>4.67 ± 0.72</td><td>681</td><td>6 BALAKIN</td><td>71</td><td>OSPK e<sup>+</sup>e<sup>-</sup> → hadrons</td></tr><tr><td>4.09 ± 0.29</td><td></td><td>BIZOT</td><td>70</td><td>OSPK e<sup>+</sup>e<sup>-</sup> → hadrons</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>4.07 ± 0.13 ± 0.01</td><td>7 HOID</td><td>20</td><td>RVUE e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>γ</td></tr><tr><td>4.23 ± 0.04 ± 0.02</td><td>8 HOFERICHT... 19</td><td>20</td><td>RVUE e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>4.249 ± 0.015</td><td>1.7M</td><td>KOZYREV</td><td>18</td><td>CMD3 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>4.240 ± 0.017</td><td>610k</td><td>KOZYREV</td><td>16</td><td>CMD3 e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>L</sub></td></tr><tr><td>4.37 ± 0.02</td><td></td><td>LEES</td><td>13F</td><td>BABR D<sup>+</sup> → K<sup>+</sup>K<sup>-</sup>π<sup>+</sup></td></tr><tr><td>4.24 ± 0.02 ± 0.03</td><td>542k</td><td>9 AKHMETSHIN 08</td><td>18</td><td>CMD2 1.02 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>4.28 ± 0.13</td><td>12540</td><td>10 AUBERT, B</td><td>05J</td><td>BABR D<sup>0</sup> → K<sup>0</sup> K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>4.45 ± 0.06</td><td>271k</td><td>DIJKSTRA</td><td>86</td><td>SPEC 100 π<sup>-</sup>Be</td></tr><tr><td>3.6 ± 0.8</td><td>337</td><td>6 COOPER</td><td>78B</td><td>HBC 0.7-0.8 βp → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>L</sub>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>4.5 ± 0.50</td><td>1300</td><td>6,10 AKERLOF</td><td>77</td><td>SPEC 400 pA → K<sup>+</sup>K<sup>-</sup>X</td></tr><tr><td>4.5 ± 0.8</td><td>500</td><td>6,10 AYRES</td><td>74</td><td>ASPK 3-6 π<sup>-</sup> p → K<sup>+</sup>K<sup>-</sup>n, K<sup>-</sup>p → K<sup>+</sup>K<sup>-</sup>Λ/Σ<sup>0</sup></td></tr><tr><td>3.81 ± 0.37</td><td></td><td>COSME</td><td>74B</td><td>OSPK e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>S</sub></td></tr><tr><td>3.8 ± 0.7</td><td>454</td><td>6 BORENSTEIN</td><td>72</td><td>HBC 2.18 K<sup>-</sup>p → K Kπn</td></tr></tbody></table>

¹ Average of KOZYREV 16 and KOZYREV 18 values taking into account the correlated uncertainties. Supersedes individual KOZYREV 16 and KOZYREV 18 results.

² Using a vector meson dominance model with contribution from $\phi(1020)$ and higher mass excitations of $\rho(770)$, $\omega(782)$, and $\phi(1020)$.

³ Using a phenomenological model based on KUHN 90 with a sum of Breit-Wigner resonances for $\rho(770)$, $\omega(782)$, $\phi(1020)$ and their higher mass excitations.

⁴ Update of AKHMETSHIN 99D

⁵ From the combined fit assuming that the total $\phi(1020)$ production cross section is saturated by those of $K^+K^-$, $K_S K_L$, $\pi^+\pi^-$, and $\eta\gamma$ decays modes and using ACHASOV 00B for the $\eta\gamma$ decay mode.

⁶ Width errors enlarged by us to $4\Gamma/\sqrt{N}$; see the note with the $K^*(892)$ mass.

⁷ The values were extracted from a dispersively improved Breit-Wigner parameterization.

⁸ The values were extracted from a dispersively improved Breit-Wigner parameterization and do not include vacuum polarization.

⁹ Strongly correlated with AKHMETSHIN 04.

¹⁰ Systematic errors not evaluated.

## $\phi(1020)$ DECAY MODES

<table><thead><tr><th>Mode</th><th>Fraction (Γ<sub>i</sub>/Γ)</th><th>Scale factor/<br>Confidence level</th></tr></thead><tbody><tr><td>Γ<sub>1</sub></td><td>K<sup>+</sup>K<sup>-</sup></td><td>(49.1 ± 0.5 ) %</td><td>S=1.3</td></tr><tr><td>Γ<sub>2</sub></td><td>K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub></td><td>(33.9 ± 0.4 ) %</td><td>S=1.2</td></tr><tr><td>Γ<sub>3</sub></td><td>ρπ + π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td><td>(15.4 ± 0.4 ) %</td><td>S=1.2</td></tr><tr><td>Γ<sub>4</sub></td><td>π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td><td></td><td></td></tr><tr><td>Γ<sub>5</sub></td><td>ηγ</td><td>( 1.301 ± 0.024 ) %</td><td>S=1.2</td></tr><tr><td>Γ<sub>6</sub></td><td>π<sup>0</sup>γ</td><td>( 1.32 ± 0.05 ) × 10<sup>-3</sup></td><td></td></tr><tr><td>Γ<sub>7</sub></td><td>ℓ<sup>+</sup>ℓ<sup>-</sup></td><td>—</td><td></td></tr><tr><td>Γ<sub>8</sub></td><td>e<sup>+</sup>e<sup>-</sup></td><td>( 2.979 ± 0.033 ) × 10<sup>-4</sup></td><td>S=1.2</td></tr><tr><td>Γ<sub>9</sub></td><td>μ<sup>+</sup>μ<sup>-</sup></td><td>( 2.85 ± 0.22 ) × 10<sup>-4</sup></td><td>S=1.2</td></tr><tr><td>Γ<sub>10</sub></td><td>ηe<sup>+</sup>e<sup>-</sup></td><td>( 1.08 ± 0.04 ) × 10<sup>-4</sup></td><td></td></tr></tbody></table>

<table><tbody><tr><td>Γ<sub>11</sub></td><td>π<sup>+</sup>π<sup>-</sup></td><td>( 7.3 ± 1.3 ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>12</sub></td><td>ωπ<sup>0</sup></td><td>( 4.7 ± 0.5 ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>13</sub></td><td>ωγ</td><td>&lt; 5 %</td><td>CL=84%</td></tr><tr><td>Γ<sub>14</sub></td><td>ργ</td><td>&lt; 1.2 × 10<sup>-5</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>15</sub></td><td>π<sup>+</sup>π<sup>-</sup>γ</td><td>( 4.1 ± 1.3 ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>16</sub></td><td>f<sub>0</sub>(980)γ</td><td>( 3.22 ± 0.19 ) × 10<sup>-4</sup></td><td>S=1.1</td></tr><tr><td>Γ<sub>17</sub></td><td>π<sup>0</sup>π<sup>0</sup>γ</td><td>( 1.12 ± 0.06 ) × 10<sup>-4</sup></td><td></td></tr><tr><td>Γ<sub>18</sub></td><td>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td><td>( 3.9 <sup>+2.8</sup><sub>-2.2</sub> ) × 10<sup>-6</sup></td><td></td></tr><tr><td>Γ<sub>19</sub></td><td>π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>π<sup>-</sup>π<sup>0</sup></td><td>&lt; 4.6 × 10<sup>-6</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>20</sub></td><td>π<sup>0</sup>e<sup>+</sup>e<sup>-</sup></td><td>( 1.33 <sup>+0.07</sup><sub>-0.10</sub> ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>21</sub></td><td>π<sup>0</sup>ηγ</td><td>( 7.27 ± 0.30 ) × 10<sup>-5</sup></td><td>S=1.5</td></tr><tr><td>Γ<sub>22</sub></td><td>a<sub>0</sub>(980)γ</td><td>( 7.6 ± 0.6 ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>23</sub></td><td>K<sup>0</sup> R<sup>0</sup>γ</td><td>&lt; 1.9 × 10<sup>-8</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>24</sub></td><td>η<sup>0</sup>(958)γ</td><td>( 6.21 ± 0.20 ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>25</sub></td><td>ηπ<sup>0</sup>π<sup>0</sup>γ</td><td>&lt; 2 × 10<sup>-5</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>26</sub></td><td>μ<sup>+</sup>μ<sup>-</sup>γ</td><td>( 1.4 ± 0.5 ) × 10<sup>-5</sup></td><td></td></tr><tr><td>Γ<sub>27</sub></td><td>ργγ</td><td>&lt; 1.2 × 10<sup>-4</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>28</sub></td><td>ηπ<sup>+</sup>π<sup>-</sup></td><td>&lt; 1.8 × 10<sup>-5</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>29</sub></td><td>ημ<sup>+</sup>μ<sup>-</sup></td><td>&lt; 9.4 × 10<sup>-6</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>30</sub></td><td>ηU → ηe<sup>+</sup>e<sup>-</sup></td><td>&lt; 1 × 10<sup>-6</sup></td><td>CL=90%</td></tr><tr><td>Γ<sub>31</sub></td><td>invisible</td><td>&lt; 1.7 × 10<sup>-4</sup></td><td>CL=90%</td></tr></tbody></table>

## Lepton Family number (LF) violating modes

<table><tr><td>Γ<sub>32</sub></td><td>e<sup>±</sup>μ<sup>±</sup></td><td>LF &lt; 2 × 10<sup>-6</sup></td><td>CL=90%</td></tr></table>

## CONSTRAINED FIT INFORMATION

An overall fit to 30 branching ratios uses 80 measurements and one constraint to determine 14 parameters. The overall fit has a $\chi^2 = 61.8$ for 67 degrees of freedom.

The following off-diagonal array elements are the correlation coefficients $\langle\delta\xi_i\delta x_j\rangle/(\delta\xi_i\delta x_j)$, in percent, from the fit to the branching fractions, $x_i \equiv \Gamma_i/\Gamma_{\text{total}}$. The fit constrains the $x_i$ whose labels appear in this array to sum to one.

<table><tbody><tr><td>x<sub>2</sub></td><td>-72</td></tr><tr><td>x<sub>3</sub></td><td>-61 -12</td></tr><tr><td>x<sub>5</sub></td><td>-19 17 2</td></tr><tr><td>x<sub>6</sub></td><td>-11 11 1 8</td></tr><tr><td>x<sub>8</sub></td><td>47 -50 -8 -35 -22</td></tr><tr><td>x<sub>9</sub></td><td>-5 4 1 3 2 -9</td></tr><tr><td>x<sub>11</sub></td><td>-3 3 0 2 1 -6 1</td></tr><tr><td>x<sub>12</sub></td><td>-4 4 1 3 2 -8 1 0</td></tr><tr><td>x<sub>16</sub></td><td>0 0 0 0 0 0 0 0</td></tr><tr><td>x<sub>17</sub></td><td>-9 9 1 18 4 -18 2 1 0 1</td></tr><tr><td>x<sub>18</sub></td><td>-1 1 0 1 0 -2 0 0 0 0</td></tr><tr><td>x<sub>22</sub></td><td>0 0 0 0 0 0 0 0 0</td></tr><tr><td>x<sub>24</sub></td><td>-6 5 1 32 2 -11 1 1 1 0</td></tr><tr><td>x<sub>1</sub></td><td>x<sub>2</sub></td><td>x<sub>3</sub></td><td>x<sub>5</sub></td><td>x<sub>6</sub></td><td>x<sub>8</sub></td><td>x<sub>9</sub></td><td>x<sub>11</sub></td><td>x<sub>12</sub></td><td>x<sub>16</sub></td></tr><tr><td>x<sub>18</sub></td><td>0</td></tr><tr><td>x<sub>22</sub></td><td>0</td></tr><tr><td>x<sub>24</sub></td><td>6 0 0 0</td></tr><tr><td>x<sub>17</sub></td><td>x<sub>18</sub></td><td>x<sub>22</sub></td></tr></tbody></table>

## $\phi(1020)$ PARTIAL WIDTHS

<table><thead><tr><th>Γ(ηγ)</th><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td></td><td></td><td></td><td></td><td>• • • We do not use the following data for averages, fits, limits, etc. • • •</td></tr><tr><td></td><td>58.9 ± 0.5 ± 2.4</td><td>ACHASOV</td><td>00</td><td>SND e<sup>+</sup>e<sup>-</sup> → ηγ</td></tr></tbody></table>

<table><thead><tr><th>Γ(π<sup>0</sup>γ)</th><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td></td><td></td><td></td><td></td><td>• • • We do not use the following data for averages, fits, limits, etc. • • •</td></tr><tr><td></td><td>5.40 ± 0.16 <sup>+0.43</sup><sub>-0.40</sub></td><td>ACHASOV</td><td>00</td><td>SND e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>γ</td></tr></tbody></table>

<table><thead><tr><th>Γ(ℓ<sup>+</sup>ℓ<sup>-</sup>)</th><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

1.320 ± 0.017 ± 0.015
1 AMBROSINO 05 KLOE 1.02 e<sup>+</sup>e<sup>-</sup> → μ<sup>+</sup>μ<sup>-</sup>

¹ Weighted average of $\Gamma_{ee}$ and $\sqrt{\Gamma_{ee}\Gamma_{\mu\mu}}$ from AMBROSINO 05 assuming lepton universality.
$\Gamma(e^{+}e^{-})$

<table><thead><tr><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

1.27 ±0.04 OUR EVALUATION

1.251 ±0.021 OUR AVERAGE Error includes scale factor of 1.1.

$1.235 \pm 0.006 \pm 0.022$

$1 \text{ AKHMETSHIN } 11 \text{ CMD2 } 1.02 e^{+} e^{-} \rightarrow \phi$

$1.32 \pm 0.05 \pm 0.03$

$2 \text{ AMBROSINO } 05 \text{ CMD3 } 1.02 e^{+} e^{-} \rightarrow e^{+} e^{-}$

$1.28 \pm 0.05$

$1 \text{ AKHMETSHIN } 95 \text{ CMD2 } 1.02 e^{+} e^{-} \rightarrow \phi$

1 Combined analysis of the CMD-2 data on $\phi \rightarrow K^{+}K^{-}, K_{S}^{0}K_{L}^{0}, \pi^{+}\pi^{-}\pi^{0}, \eta\gamma$ assuming that the sum of their branching fractions is 0.99741 $\pm$ 0.00007.

2 From forward-backward asymmetry and using $\Gamma_{\text{total}} = 4.26 \pm 0.05$ MeV from the 2004 edition of this Review.

$$(\Gamma(e^{+}e^{-}) \times \Gamma(\mu^{+}\mu^{-}))^{1/2}$$

<table><thead><tr><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

$1.320 \pm 0.018 \pm 0.017$

$\phi(1020) \Gamma(i)\Gamma(e^{+}e^{-})/\Gamma(\text{total})$

$\Gamma(K^{+}K^{-}) \times \Gamma(e^{+}e^{-})/\Gamma_{\text{total}}$

<table><thead><tr><th>VALUE (keV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

$0.6340 \pm 0.0070 \pm 0.0039$

$1 \text{ LEES } 13Q \text{ BABR } e^{+} e^{-} \rightarrow K^{+} K^{-} \gamma$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$0.669 \pm 0.001 \pm 0.023$

$1.7M \text{ KOZYREV } 18 \text{ CMD3 } e^{+} e^{-} \rightarrow K^{+} K^{-}$

1 Using a phenomenological model based on KUHN 90 with a sum of Breit-Wigner resonances for $\rho(770)$, $\omega(782)$, $\phi(1020)$ and their higher mass excitations. The first error combines statistical and systematic uncertainties. The second one is due to the parametrization of the charged kaon form factor and mass calibration.

$\Gamma(K_{S}^{0}K_{S}^{0}) \times \Gamma(e^{+}e^{-})/\Gamma_{\text{total}}$

<table><thead><tr><th>VALUE (keV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

$0.4200 \pm 0.0033 \pm 0.0123$

$28k \text{ 1 LEES } 14H \text{ BABR } e^{+} e^{-} \rightarrow K_{S}^{0} K_{L}^{0} \gamma$

1 Using a vector meson dominance model with contribution from $\phi(1020)$ and higher mass excitations of $\rho(770)$, $\omega(782)$, and $\phi(1020)$.

$$[\Gamma(\rho\pi) + \Gamma(\pi^+\pi^-\pi^0)] \times \Gamma(e^+e^-)/\Gamma_{\text{total}}$$

<table><thead><tr><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

$184.1 \pm 2.1 \pm 6.0$

$1 \text{ LEES } 21B \text{ BABR } 10.5 e^{+} e^{-} \rightarrow \pi^{+} \pi^{-} \pi^{0} \gamma$

1 From the cross section for $e^{+} e^{-} \rightarrow \pi^{+} \pi^{-} \pi^{0}$ with contributions from $\rho(770)$, $\omega(782)$, $\phi(1020)$, $\omega(1420)$, and $\omega(1650)$.

$\phi(1020) \Gamma(i)\Gamma(e^{+}e^{-})/\Gamma^{2}(\text{total})$

$\Gamma(K^{+}K^{-})/\Gamma_{\text{total}} \times \Gamma(e^{+}e^{-})/\Gamma_{\text{total}}$

<table><thead><tr><th>VALUE (units 10<sup>-5</sup>)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

$14.64 \pm 0.27$

OUR FIT Error includes scale factor of 1.4.

$14.6 \pm 0.5$

OUR AVERAGE Error includes scale factor of 1.8. See the ideogram below.

$15.789 \pm 0.541$

$1.7M$

$18 \text{ KOZYREV } 18 \text{ CMD3 } e^{+} e^{-} \rightarrow K^{+} K^{-}$

$14.27 \pm 0.05 \pm 0.31$

$542k$

$18 \text{ AKHMETSHIN } 08 \text{ CMD2 } 1.02 e^{+} e^{-} \rightarrow K^{+} K^{-}$

$13.93 \pm 0.14 \pm 0.99$

$1000k$

$1 \text{ ACHASOV } 01E \text{ SND } e^{+} e^{-} \rightarrow K^{+} K^{-}, K_{S} K_{L}, \pi^{+} \pi^{-} \pi^{0}$

1 From the combined fit assuming that the total $\phi(1020)$ production cross section is saturated by those of $K^{+}K^{-}, K_{S}K_{L}, \pi^{+}\pi^{-}\pi^{0}$, and $\eta\gamma$ decays modes and using ACHASOV 00B for the $\eta\gamma$ decay mode.

<figure><img src="image_445.png" /><figcaption>WEIGHTED AVERAGE
14.6±0.5 (Error scaled by 1.8)</figcaption></figure>

$\Gamma(K_{L}^{0}K_{S}^{0})/\Gamma_{\text{total}} \times \Gamma(e^{+}e^{-})/\Gamma_{\text{total}}$

<table><thead><tr><th>VALUE (units 10<sup>-5</sup>)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

10.11 ±0.12 OUR FIT

10.07 ±0.13 OUR AVERAGE

$10.078 \pm 0.223$

$1 \text{ KOZYREV } 16 \text{ CMD3 } e^{+} e^{-} \rightarrow K_{S}^{0} K_{L}^{0}$

$10.01 \pm 0.04 \pm 0.17$

$2 \text{ AKHMETSHIN } 04 \text{ CMD2 } e^{+} e^{-} \rightarrow K_{S}^{0} K_{L}^{0}$

$10.27 \pm 0.07 \pm 0.34$

$3 \text{ ACHASOV } 01E \text{ SND } e^{+} e^{-} \rightarrow K^{+} K^{-}, K_{S} K_{L}, \pi^{+} \pi^{-} \pi^{0}$

1 KOZYREV 16 also reports $\Gamma(e^{+}e^{-}) B(\phi \rightarrow K_{S}^{0} K_{L}^{0}) = (0.428 \pm 0.001 \pm 0.009)$ keV.

2 Update of AKHMETSHIN 99D

3 From the combined fit assuming that the total $\phi(1020)$ production cross section is saturated by those of $K^{+}K^{-}, K_{S}K_{L}, \pi^{+}\pi^{-}\pi^{0}$, and $\eta\gamma$ decays modes and using ACHASOV 00B for the $\eta\gamma$ decay mode.

$$[\Gamma(\rho\pi) + \Gamma(\pi^{+}\pi^{-}\pi^{0})]/\Gamma_{\text{total}} \times \Gamma(e^{+}e^{-})/\Gamma_{\text{total}}$$

<table><thead><tr><th>VALUE (units 10<sup>-5</sup>)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

4.58 ±0.11 OUR FIT

Error includes scale factor of 1.1.

4.51 ±0.14 OUR AVERAGE

$4.51 \pm 0.16 \pm 0.11$

$1 \text{ AKHMETSHIN } 06 \text{ CMD2 } 0.98-1.06 e^{+} e^{-} \rightarrow \pi^{+} \pi^{-} \pi^{0}$

$4.665 \pm 0.042 \pm 0.261$

$1 \text{ ACHASOV } 01E \text{ SND } e^{+} e^{-} \rightarrow K^{+} K^{-}$

$4.35 \pm 0.27 \pm 0.08$

$2 \text{ AKHMETSHIN } 98 \text{ CMD2 } e^{+} e^{-} \rightarrow \pi^{+} \pi^{-} \pi^{0}$

$4.38 \pm 0.12$

$1 \text{ BENAYOUN } 10 \text{ RVUE } 0.4-1.05 e^{+} e^{-}$

• • • We do not use the following data for averages, fits, limits, etc. • • •

• • • We do not use the following data for averages, fits, limits, etc. • • •

$4.30 \pm 0.08 \pm 0.21$

$3 \text{ AUBERT,B } 04N \text{ BABR } 10.6 e^{+} e^{-} \rightarrow \pi^{+} \pi^{-} \pi^{0} \gamma$

1 From the combined fit assuming that the total $\phi(1020)$ production cross section is saturated by those of $K^{+}K^{-}, K_{S}K_{L}, \pi^{+}\pi^{-}\pi^{0}$, and $\eta\gamma$ decays modes and using ACHASOV 00B for the $\eta\gamma$ decay mode.

2 Recalculated by us from the cross section in the peak.

3 Superseded by LEES 21B.

$\Gamma(\eta\gamma)/\Gamma_{\text{total}} \times \Gamma(e^{+}e^{-})/\Gamma_{\text{total}}$

<table><thead><tr><th>VALUE (units 10<sup>-5</sup>)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead></table>

3.88 ±0.07 OUR FIT

Error includes scale factor of 1.2.

3.93 ±0.09 OUR AVERAGE

Error includes scale factor of 1.3. See the ideogram below.

$4.050 \pm 0.067 \pm 0.118$

$33k \text{ 1 ACHASOV } 07B \text{ SND } 0.6-1.38 e^{+} e^{-} \rightarrow \eta\gamma$

$4.093 \pm 0.040 \pm 0.247$

$17.4k \text{ 2 AKHMETSHIN } 05 \text{ CMD2 } 0.60-1.38 e^{+} e^{-} \rightarrow \eta\gamma$

$3.850 \pm 0.041 \pm 0.159$

$23k \text{ 3.4 AKHMETSHIN } 01B \text{ CMD2 } e^{+} e^{-} \rightarrow \eta\gamma$

$4.00 \pm 0.04 \pm 0.11$

$5 \text{ ACHASOV } 00 \text{ SND } e^{+} e^{-} \rightarrow \eta\gamma$

$3.53 \pm 0.08 \pm 0.17$

$2200 \text{ 6.7 AKHMETSHIN } 99F \text{ CMD2 } e^{+} e^{-} \rightarrow \eta\gamma$

$4.19 \pm 0.06$

$8 \text{ BENAYOUN } 10 \text{ RVUE } 0.4-1.05 e^{+} e^{-}$

1 From a combined fit of $\sigma(e^{+} e^{-} \rightarrow \eta\gamma)$ with $\eta \rightarrow 3\pi^{0}$ and $\eta \rightarrow \pi^{+} \pi^{-} \pi^{0}$, and fixing $B(\eta \rightarrow 3\pi^{0}) / B(\eta \rightarrow \pi^{+} \pi^{-} \pi^{0}) = 1.44 \pm 0.04$. Recalculated by us from the cross section at the peak. Supersedes ACHASOV 00B and ACHASOV 06A.

2 From the $\eta \rightarrow 2\gamma$ decay and using $B(\eta \rightarrow \gamma\gamma) = 39.43 \pm 0.26\%$.

3 From the $\eta \rightarrow 3\pi^{0}$ decay and using $B(\eta \rightarrow 3\pi^{0}) = (32.24 \pm 0.29) \times 10^{-2}$.

4 The combined fit from 600 to 1380 MeV taking into account $\rho(770)$, $\omega(782)$, $\phi(1020)$, and $\rho(1450)$ (mass and width fixed at 1450 MeV and 310 MeV respectively).

5 From the $\eta \rightarrow 2\gamma$ decay and using $B(\eta \rightarrow 2\gamma) = (39.21 \pm 0.34) \times 10^{-2}$.

6 Recalculated by the authors from the cross section in the peak.

7 From the $\eta \rightarrow \pi^{+}\pi^{-}\pi^{0}$ decay and using $B(\eta \rightarrow \pi^{+}\pi^{-}\pi^{0}) = (23.1 \pm 0.5) \times 10^{-2}$.

8 A simultaneous fit of $e^{+} e^{-} \rightarrow \pi^{+} \pi^{-}, \pi^{+}\pi^{-}\pi^{0}, \pi^{0}\gamma, \eta\gamma$ data.

<figure><img src="image_446.png" /><figcaption>WEIGHTED AVERAGE
3.93±0.09 (Error scaled by 1.3)</figcaption></figure>

Values above of weighted average, error, and scale factor are based upon the data in this ideogram only. They are not necessarily the same as our 'best' values, obtained from a least-squares constrained fit utilizing measurements of other (related) quantities as additional information.
$$ \Gamma(\pi^0\gamma)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_6/\Gamma \times \Gamma_8/\Gamma $$

VALUE (units 10⁻⁷) EVTS

DOCUMENT ID TECN COMMENT

### 3.94±0.16 OUR FIT

### 3.95±0.17 OUR AVERAGE

<table><tr><td>4.04±0.09±0.19</td><td>1 ACHASOV</td><td>16A</td><td>SND</td><td>0.60-1.38 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>γ</td></tr><tr><td>3.75±0.11±0.29</td><td>18k</td><td>AKHMETSHIN</td><td>05</td><td>CMD2 0.60-1.38 e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>γ</td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

4.29±0.11 2 BENAYOUN 10 RVUE 0.4-1.05 e<sup>+</sup>e<sup>-</sup>

3.67±0.10<sup>+0.27</sup><sub>-0.25</sub> 3 ACHASOV 00 SND e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>γ

¹ From the VMD model with the interfering $\rho(770)$, $\omega(782)$, $\phi(1020)$ resonances, and an additional resonance describing the total contribution of the $\rho(1450)$ and $\omega(1420)$ states. Supersedes ACHASOV 00.

² A simultaneous fit of $e^+e^-$ → $\pi^+\pi^-$, $\pi^+\pi^-\pi^0$, $\pi^0\gamma$, $\eta\gamma$ data.

³ From the $\pi^0 \to 2\gamma$ decay and using $B(\pi^0 \to 2\gamma) = (98.798 \pm 0.032) \times 10^{-2}$.

$$ \Gamma(\mu^+\mu^-)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_9/\Gamma \times \Gamma_8/\Gamma $$

VALUE (units 10⁻⁸) EVTS

DOCUMENT ID TECN COMMENT

8.5 ±0.6 OUR FIT Error includes scale factor of 1.2.

8.8 ±0.9 OUR AVERAGE Error includes scale factor of 1.5. See the ideogram below.

8.36 ±0.59±0.37 ACHASOV 01G SND e<sup>+</sup>e<sup>-</sup> → μ<sup>+</sup>μ<sup>-</sup>

9.9 ±1.4 ±0.9 1 ACHASOV 99C SND e<sup>+</sup>e<sup>-</sup> → μ<sup>+</sup>μ<sup>-</sup>

14.4 ±3.0 2 VASSERMAN 81 OLYA e<sup>+</sup>e<sup>-</sup> → μ<sup>+</sup>μ<sup>-</sup>

8.6 ±5.9 3 AUGUSTIN 73 OSPK e<sup>+</sup>e<sup>-</sup> → μ<sup>+</sup>μ<sup>-</sup>

¹ Recalculated by the authors from the cross section in the peak.

² Recalculated by us from the cross section in the peak.

### WEIGHTED AVERAGE

8.8±0.9 (Error scaled by 1.5)

<figure><img src="image_447.png" /></figure>

Values above of weighted average, error, and scale factor are based upon the data in this ideogram only. They are not necessarily the same as our 'best' values, obtained from a least-squares constrained fit utilizing measurements of other (related) quantities as additional information.

$$ \Gamma(\mu^+\mu^-)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_9/\Gamma \times \Gamma_8/\Gamma $$

$$ \Gamma(\pi^+\pi^-)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_{11}/\Gamma \times \Gamma_8/\Gamma $$

VALUE (units 10⁻⁸) EVTS

DOCUMENT ID TECN COMMENT

### 2.2 ±0.4 OUR FIT

### 2.2 ±0.4 OUR AVERAGE

2.1 ±0.3 ±0.3 1 ACHASOV 00C SND e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>

1.95<sup>+1.15</sup><sub>-0.87</sub> 2 GOLUBEV 86 ND e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>

6.01<sup>+3.19</sup><sub>-2.51</sub> 2 VASSERMAN 81 OLYA e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>

• • • We do not use the following data for averages, fits, limits, etc. • • •

3.31±0.99 3 BENAYOUN 13 RVUE 0.4-1.05 e<sup>+</sup>e<sup>-</sup>

¹ Recalculated by the authors from the cross section in the peak.

² Recalculated by us from the cross section in the peak.

³ A simultaneous fit to $e^+e^-$ → $\pi^+\pi^-$, $\pi^+\pi^-\pi^0$, $\pi^0\gamma$, $\eta\gamma$, $K\bar{K}$, and $\tau^- \to \pi^-\pi^0\nu_\tau$ data.

$$ \Gamma(\omega^0)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_{12}/\Gamma \times \Gamma_8/\Gamma $$

VALUE (units 10⁻⁸) EVTS

DOCUMENT ID TECN COMMENT

### 1.40±0.15 OUR FIT

1.37±0.17±0.01 1.2 AMBROSINO 08G KLOE e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>2π<sup>0</sup>, 2π<sup>0</sup>γ

¹ Recalculated by the authors from the cross section at the peak.

² AMBROSINO 08G reports $[\Gamma(\phi(1020) \to \omega^0)/\Gamma_{\text{total}} \times \Gamma(\phi(1020) \to e^+e^-)]/\Gamma_{\text{total}} \times [B(\omega(782) \to \pi^+\pi^-\pi^0) = (1.22 \pm 0.13 \pm 0.08) \times 10^{-8}$ which we divide by our best value $B(\omega(782) \to \pi^+\pi^-\pi^0) = (89.2 \pm 0.7) \times 10^{-2}$.

$$ \Gamma(\pi^0\pi^0\gamma)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_{17}/\Gamma \times \Gamma_8/\Gamma $$

VALUE (units 10⁻⁸) EVTS

DOCUMENT ID TECN COMMENT

### 3.34±0.17 OUR FIT

3.33<sup>+0.04</sup><sub>-0.09</sub>±0.19 1 AMBROSINO 07 KLOE e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ

¹ Calculated by the authors from the cross section at the peak.

$$ \Gamma(\pi^+\pi^-\pi^+\pi^-)/\Gamma_{\text{total}} \times \Gamma(e^+e^-)/\Gamma_{\text{total}} \quad \Gamma_{18}/\Gamma \times \Gamma_8/\Gamma $$

VALUE (units 10⁻⁹) EVTS

DOCUMENT ID TECN COMMENT

### 1.2 ±0.8<sup>+0.7</sup> OUR FIT

1.17±0.52±0.64 3285 1 AKHMETSHIN 00E CMD2 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>

¹ Recalculated by the authors from the cross section in the peak.

## $\phi(1020)$ BRANCHING RATIOS

$$ \Gamma(K^+K^-)/\Gamma_{\text{total}} \quad \Gamma_1/\Gamma $$

VALUE (units 10⁻⁹) EVTS

DOCUMENT ID TECN COMMENT

0.491±0.005 OUR FIT Error includes scale factor of 1.3.

### 0.493±0.010 OUR AVERAGE

<table><tr><td>0.492±0.012</td><td>2913</td><td>AKHMETSHIN 95</td><td>CMD2 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>0.44 ±0.05</td><td>321</td><td>KALBFLEISCH 76</td><td>HBC 2.18 K<sup>-</sup>p → ΛK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>0.49 ±0.06</td><td>270</td><td>DEGROOT 74</td><td>HBC 4.2 K<sup>-</sup>p → Λφ</td></tr><tr><td>0.540±0.034</td><td>565</td><td>BALAKIN 71</td><td>OSPK e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>0.48 ±0.04</td><td>252</td><td>LINDSEY 66</td><td>HBC 2.1-2.7 K<sup>-</sup>p → ΛK<sup>+</sup>K<sup>-</sup></td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

0.493±0.003±0.007 1 AKHMETSHIN 11 CMD2 1.02 e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>

0.476±0.017 1000k 2 ACHASOV 01E SND e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>, K<sub>S</sub>K<sub>L</sub>.

¹ Combined analysis of the CMD-2 data on $\phi \to K^+K^-$, $K^0_S K^0_S$, $\pi^+\pi^0$, $\eta\gamma$ assuming that the sum of their branching fractions is 0.99741 ± 0.00007.

² Using $B(\phi \to e^+e^-) = (2.93 \pm 0.14) \times 10^{-4}$.

$$ \Gamma(K_L^0 K_S^0)/\Gamma_{\text{total}} \quad \Gamma_2/\Gamma $$

VALUE (units 10⁻⁹) EVTS

DOCUMENT ID TECN COMMENT

0.339±0.004 OUR FIT Error includes scale factor of 1.2.

### 0.331±0.009 OUR AVERAGE

<table><tr><td>0.335±0.010</td><td>40644</td><td>AKHMETSHIN 95</td><td>CMD2 e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>S</sub></td></tr><tr><td>0.326±0.035</td><td>500k</td><td>DOLINSKY 91</td><td>ND e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>S</sub></td></tr><tr><td>0.310±0.024</td><td>84</td><td>DRUZHININ 84</td><td>ND e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub></td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

0.336±0.002±0.006 1 AKHMETSHIN 11 CMD2 1.02 e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>L</sub>

0.351±0.013 500k 2 ACHASOV 01E SND e<sup>+</sup>e<sup>-</sup> → K<sup>+</sup>K<sup>-</sup>, K<sub>S</sub>K<sub>L</sub>.

0.27 ±0.03 133 KALBFLEISCH 76 HBC 2.18 K<sup>-</sup>p → ΛK<sup>0</sup><sub>S</sub>K<sup>0</sup><sub>S</sub>

0.257±0.030 95 3 BALAKIN 71 OSPK e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub>

0.40 ±0.04 167 LINDSEY 66 HBC 2.1-2.7 K<sup>-</sup>p → ΛK<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub>

¹ Combined analysis of the CMD-2 data on $\phi \to K^+K^-$, $K^0_S K^0_S$, $\pi^+\pi^0$, $\eta\gamma$ assuming that the sum of their branching fractions is 0.99741 ± 0.00007.

² Using $B(\phi \to e^+e^-) = (2.93 \pm 0.14) \times 10^{-4}$.

³ Balakin error increased by Paul.

$$ \Gamma(K_L^0 K_S^0)/\Gamma(K^+K^-) \quad \Gamma_2/\Gamma_1 $$

VALUE (units 10⁻⁹) EVTS

DOCUMENT ID TECN COMMENT

0.690±0.014 OUR FIT Error includes scale factor of 1.3.

### 0.740±0.031 OUR AVERAGE

<table><tr><td>0.70 ±0.06</td><td>2732</td><td>BUKIN 78C OLYA e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub></td></tr><tr><td>0.82 ±0.08</td><td>LOSTY 78</td><td>HBC 4.2 K<sup>-</sup>p → φhyperon</td></tr><tr><td>0.71 ±0.05</td><td>LAVEN 77</td><td>HBC 10 K<sup>-</sup>p → K<sup>+</sup>K<sup>-</sup>Λ</td></tr><tr><td>0.71 ±0.08</td><td>LYONS 77</td><td>HBC 3-4 K<sup>-</sup>p → Λφ</td></tr><tr><td>0.89 ±0.10</td><td>144</td><td>AGUILAR-... 72B HBC 3.9,4.6 K<sup>-</sup>p</td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

0.638±0.022 2.3M 1 KOZYREV 18 CMD3 e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub>

0.68 ±0.03 2 AKHMETSHIN 95 CMD2 e<sup>+</sup>e<sup>-</sup> → K<sup>0</sup><sub>L</sub>K<sup>0</sup><sub>S</sub>, K<sup>+</sup>K<sup>-</sup>

¹ The prediction taking into account phase-space difference, radiative corrections, isospin breaking, and the Sommerfeld-Gamow-Sakharov factor gives 0.630.

² Theoretical analysis of BRAMON 00 taking into account phase-space difference, electromagnetic radiative corrections, as well as isospin breaking, predicts 0.62. FLOREZ-BAEZ 08 predicts 0.63 considering also structure-dependent radiative corrections. FISCHBACH 02 calculates additional corrections caused by the close threshold and predicts 0.68. See also BENAYOUN 01 and DUBYNSKIY 07. BENAYOUN 12 obtains 0.71 ± 0.01 in the HLS model.

$$ \Gamma(K_L^0 K_S^0)/\Gamma(K\bar{K}) \quad \Gamma_2/(\Gamma_1+\Gamma_2) $$

VALUE (units 10⁻⁹) EVTS

DOCUMENT ID TECN COMMENT

0.408±0.005 OUR FIT Error includes scale factor of 1.3.

### 0.45 ±0.04 OUR AVERAGE

<table><tr><td>0.44 ±0.07</td><td>1 LONDON 66 HBC</td><td>2.24 K<sup>-</sup>p → ΛK<sup>+</sup>K<sup>-</sup></td></tr><tr><td>0.48 ±0.07</td><td>52 BADIER 65B HBC</td><td>3 K<sup>-</sup>p</td></tr><tr><td>0.40 ±0.10</td><td>34 SCHLEIN 63 HBC</td><td>1.95 K<sup>-</sup>p → ΛK<sup>+</sup>K<sup>-</sup></td></tr></table>

¹ This is probably not affected by their controversial background subtraction; the value is from their numbers of $K_1 K_2$ vs $K^+ K^-$ events.

$$ [\Gamma(\rho\pi^+) + \Gamma(\pi^+\pi^0)]/\Gamma_{\text{total}} \quad \Gamma_3/\Gamma $$

VALUE (units 10⁻⁹) EVTS

DOCUMENT ID TECN COMMENT

0.154±0.004 OUR FIT Error includes scale factor of 1.2.

0.151±0.009 OUR AVERAGE Error includes scale factor of 1.7.

0.161±0.008 11761 AKHMETSHIN 95 CMD2 e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>

0.143±0.007 DOLINSKY 91 ND e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>
• • • We do not use the following data for averages, fits, limits, etc. • • •

0.155 ± 0.002 ± 0.005 1 AKHMETSHIN 11 CMD2 1.02 e⁺ e⁻ → π⁺π⁻ π⁰

0.159 ± 0.008 400k 2 ACHASOV 01E SND e⁺ e⁻ → K⁺ K⁻, K_S K_L, π⁺π⁻ π⁰

0.145 ± 0.009 ± 0.003 11169 3 AKHMETSHIN 98 CMD2 e⁺ e⁻ → π⁺π⁻ π⁰

0.139 ± 0.007 4 PARROUR 76B OSPK e⁺ e⁻

¹Combined analysis of the CMD-2 data on $\phi \to K^+K^-$, $K_S^0 K_L^0$, $\pi^+\pi^-\pi^0$, $\eta\gamma$ assuming that the sum of their branching fractions is 0.99741 ± 0.00007.

²Using $B(\phi \to e^+e^-) = (2.93 \pm 0.14) \times 10^{-4}$.

³Using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$.

⁴Using $\Gamma(\phi) = 4.1$ MeV. If interference between the $\rho\pi$ and $3\pi$ modes is neglected, the fraction of the $\rho\pi$ is more than 80% at the 90% confidence level.

$$ \frac{[\Gamma(\rho\pi) + \Gamma(\pi^+\pi^-\pi^0)]}{\Gamma(K^+K^-)} \quad \frac{\Gamma_3}{\Gamma_1} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$0.313 \pm 0.010 \text{ OUR FIT}$ Error includes scale factor of 1.2.

$0.28 \pm 0.09$ 34 AGUILAR... 72B HBC 3.9,4.6 K⁻ρ

$$ \frac{[\Gamma(\rho\pi) + \Gamma(\pi^+\pi^-\pi^0)]}{\Gamma(K^+K^-)} \quad \frac{\Gamma_3}{\Gamma(\Gamma_1 + \Gamma_2)} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$0.185 \pm 0.005 \text{ OUR FIT}$ Error includes scale factor of 1.2.

$0.24 \pm 0.04 \text{ OUR AVERAGE}$

$0.237 \pm 0.039$ CERRADA 77B HBC 4.2 K⁻ρ → Λ3π

$0.30 \pm 0.15$ LONDON 66 HBC 2.24 K⁻ρ → Λπ⁺π⁻π⁰

$$ \frac{[\Gamma(\rho\pi) + \Gamma(\pi^+\pi^-\pi^0)]}{\Gamma(K^0 K_S^0)} \quad \frac{\Gamma_3}{\Gamma_2} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$0.453 \pm 0.012 \text{ OUR FIT}$ Error includes scale factor of 1.1.

$0.51 \pm 0.05 \text{ OUR AVERAGE}$

$0.56 \pm 0.07$ 3681 BUKIN 78c OLYA e⁺ e⁻ → K_S^0 K_S^0, π⁺π⁻ π⁰

$0.47 \pm 0.06$ 516 COSME 74 OSPK e⁺ e⁻ → π⁺π⁻ π⁰

$$ \frac{[\Gamma(\pi^+\pi^-\pi^0)]}{\Gamma_{\text{total}}} \quad \frac{\Gamma_4}{\Gamma} $$

$\text{VALUE} \quad \text{CL%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$\approx 0.0087$ 1.98M 1.2 ALOISIO 03 KLOE 1.02 e⁺ e⁻ → π⁺π⁻ π⁰

$<0.0006$ 90 3 ACHASOV 02 SND 1.02 e⁺ e⁻ → π⁺π⁻ π⁰

$<0.23$ 90 3 CORDIER 80 DM1 e⁺ e⁻ → π⁺π⁻ π⁰

$<0.20$ 90 3 PARROUR 76 OSPK e⁺ e⁻ → π⁺π⁻ π⁰

¹From a fit without limitations on charged and neutral $\rho$ masses and widths.

²Adding the direct and $\omega\pi$ contributions and considering the interference between the $\rho\pi$ and $\pi^+\pi^-\pi^0$.

³Neglecting the interference between the $\rho\pi$ and $\pi^+\pi^-\pi^0$.

$$ \frac{[\Gamma(\eta\gamma)]}{\Gamma_{\text{total}}} \quad \frac{\Gamma_5}{\Gamma} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$1.301 \pm 0.024 \text{ OUR FIT}$ Error includes scale factor of 1.2.

$1.26 \pm 0.04 \text{ OUR AVERAGE}$

$1.246 \pm 0.025 \pm 0.057$ 10k 1 ACHASOV 98f SND e⁺ e⁻ → 7γ

$1.18 \pm 0.11$ 279 2 AKHMETSHIN 95 CMD2 e⁺ e⁻ → π⁺π⁻ 3γ

$1.30 \pm 0.06$ 3 DRUZHININ 84 ND e⁺ e⁻ → 3γ

$1.4 \pm 0.2$ 4 DRUZHININ 84 ND e⁺ e⁻ → 6γ

$0.88 \pm 0.20$ 290 KURDADZE 83c OLYA e⁺ e⁻ → 3γ

$1.35 \pm 0.29$ 77 ANDREWS 87 CNTR 6.7–10 γCu

$1.5 \pm 0.4$ 54 3 COSME 76 OSPK e⁺ e⁻

$1.38 \pm 0.02 \pm 0.02$ 5 AKHMETSHIN 11 CMD2 1.02 e⁺ e⁻ → ηγ

$1.36 \pm 0.05 \pm 0.01$ 33k 6 ACHASOV 07b SND 0.6–1.38 e⁺ e⁻ → ηγ

$1.373 \pm 0.014 \pm 0.085$ 17.4k 7.8 AKHMETSHIN 05 CMD2 0.60–1.38 e⁺ e⁻ → ηγ

$1.287 \pm 0.013 \pm 0.063$ 9.10 AKHMETSHIN 01b CMD2 e⁺ e⁻ → ηγ

$1.338 \pm 0.012 \pm 0.052$ 11 ACHASOV 00 SND e⁺ e⁻ → ηγ

$1.18 \pm 0.03 \pm 0.06$ 2200 12 AKHMETSHIN 99f CMD2 e⁺ e⁻ → ηγ

$1.21 \pm 0.07$ 96 RVUE 0.54–1.04 e⁺ e⁻ → ηγ

¹Using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$ and $B(\eta \to 3\pi^0) = (32.2 \pm 0.4) \times 10^{-2}$.

²From $\pi^+\pi^-\pi^0$ decay mode of $\eta$.

³From 2γ decay mode of $\eta$.

⁴From $3\pi^0$ decay mode of $\eta$.

⁵Combined analysis of the CMD-2 data on $\phi \to K^+K^-$, $K_S^0 K_S^0$, $\pi^+\pi^-\pi^0$, $\eta\gamma$ assuming that the sum of their branching fractions is 0.99741 ± 0.00007.

⁶ACHASOV 07b reports $[\Gamma(\phi(1020) \to \eta\gamma)/\Gamma_{\text{total}}] \times [B(\phi(1020) \to e^+e^-)] = (4.050 \pm 0.067 \pm 0.118) \times 10^{-6}$ which we divide by our best value $B(\phi(1020) \to e^+e^-) = (2.979 \pm 0.033) \times 10^{-4}$. Our first error is their experiment's error and our second error is the systematic error from using our best value. Supersedes ACHASOV 00d and ACHASOV 06a.

⁷Using $B(\phi \to e^+e^-) = (2.98 \pm 0.04) \times 10^{-4}$ and $B(\eta \to \gamma\gamma) = 39.43 \pm 0.26\%$.

⁸Not independent of the corresponding $\Gamma(\phi \to e^+e^-) \times \Gamma(\eta\gamma)/\Gamma_{\text{total}}$.

⁹Using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$ and $B(\eta \to 3\pi^0) = (32.24 \pm 0.29) \times 10^{-2}$.

¹⁰The combined fit from 600 to 1380 MeV taking into account $\rho(770)$, $\omega(782)$, $\phi(1020)$, and $\rho(1450)$ (mass and width fixed at 1450 MeV and 310 MeV respectively).

¹¹From the $\eta \to 2\gamma$ decay and using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$.

¹²From $\pi^+\pi^-\pi^0$ decay mode of $\eta$ and using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$.

¹³Reanalysis of DRUZHININ 84, DOLINSKY 89, and DOLINSKY 91 taking into account a triangle anomaly contribution.

$$ \frac{[\Gamma(\pi^0\gamma)]}{\Gamma_{\text{total}}} \quad \frac{\Gamma_{\text{EVTS}}}{\Gamma_{\text{TECN}}} \quad \frac{\Gamma_{\text{DOCUMENT ID}}}{\Gamma_{\text{COMMENT}}} \quad \Gamma_{\text{6/}\Gamma} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$1.32 \pm 0.05 \text{ OUR FIT}$

$1.31 \pm 0.13 \text{ OUR AVERAGE}$

$1.30 \pm 0.13$ DRUZHININ 84 ND e⁺ e⁻ → 3γ

$1.4 \pm 0.5$ 32 COSME 76 OSPK e⁺ e⁻

• • • We do not use the following data for averages, fits, limits, etc. • • •

$1.367 \pm 0.072$ 1 ACHASOV 16A SND 0.60–1.38 e⁺ e⁻ → π⁰γ

$1.258 \pm 0.037 \pm 0.077$ 18k 2,3 AKHMETSHIN 05 CMD2 0.60–1.38 e⁺ e⁻ → π⁰γ

$1.226 \pm 0.036 \pm 0.096$ 4 ACHASOV 00 SND e⁺ e⁻ → π⁰γ

$1.26 \pm 0.17$ 5 BENAYOUN 96 RVUE 0.54–1.04 e⁺ e⁻ → π⁰γ

¹Using $B(\phi \to e^+e^-)$ from PDG 15. Supersedes ACHASOV 00.

²Using $B(\phi \to e^+e^-) = (2.98 \pm 0.04) \times 10^{-4}$.

³Not independent of the corresponding $\Gamma(\phi \to e^+e^-) \times \Gamma(\pi^0\gamma)/\Gamma_{\text{total}}^2$.

⁴From the $\pi^0 \to 2\gamma$ decay and using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$.

⁵Reanalysis of DRUZHININ 84, DOLINSKY 89, and DOLINSKY 91 taking into account a triangle anomaly contribution.

$$ \frac{[\Gamma(\eta\gamma)]}{\Gamma_{\eta\gamma}} \quad \frac{\Gamma_{\eta\gamma}}{\Gamma_{\eta\gamma}} \quad \frac{\Gamma_{\text{EVTS}}}{\Gamma_{\text{TECN}}} \quad \Gamma_{\eta\gamma} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$10.9 \pm 0.3 \pm 0.7$ 0.8 ACHASOV 00 SND e⁺ e⁻ → $\eta\gamma, \pi^0\gamma$

$$ \frac{[\Gamma(\phi \to e^+e^-)]}{\Gamma_{\phi \to e^+e^-}} \quad \frac{\Gamma_{\phi \to e^+e^-}}{\Gamma_{\phi \to e^+e^-}} \quad \frac{\Gamma_{\phi \to e^+e^-}}{\Gamma_{\phi \to e^+e^-}} \quad \Gamma_{\phi \to e^+e^-} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$2.979 \pm 0.033 \text{ OUR FIT}$ Error includes scale factor of 1.2.

$2.90 \pm 0.07 \text{ OUR AVERAGE}$ Error includes scale factor of 1.1.

$2.93 \pm 0.14$ 1900k 1 ACHASOV 01E SND e⁺ e⁻ → K⁺K⁻, K_S K_L, $\pi^+\pi^-\pi^0$

$2.88 \pm 0.09$ 55600 AKHMETSHIN 95 CMD2 e⁺ e⁻ → hadrons

$3.00 \pm 0.21$ 3681 BUKIN 78C OLYA e⁺ e⁻ → hadrons

$3.10 \pm 0.14$ 2 PARROUR 76 OSPK e⁺ e⁻

$3.3 \pm 0.3$ COSME 74 OSPK e⁺ e⁻ → hadrons

$2.81 \pm 0.25$ BALAKIN 71 OSPK e⁺ e⁻ → hadrons

$3.50 \pm 0.27$ CHATELUS 71 OSPK e⁺ e⁻

¹From the combined fit assuming that the total $\phi(1020)$ production cross section is saturated by those of $K^+K^-$, $K_S K_L$, $\pi^+\pi^-\pi^0$, and $\eta\gamma$ decays modes and using ACHASOV 00b for the $\eta\gamma$ decay mode.

²Using total width 4.2 MeV. They detect $3\pi$ mode and observe significant interference with $\omega$ tail. This is accounted for in the result quoted above.

$$ \frac{[\Gamma(\mu^+\mu^-)]}{\Gamma_{\mu^+\mu^-}} \quad \frac{\Gamma_{\mu^+\mu^-}}{\Gamma_{\mu^+\mu^-}} \quad \frac{\Gamma_{\mu^+\mu^-}}{\Gamma_{\mu^+\mu^-}} \quad \Gamma_{\mu^+\mu^-} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$2.85 \pm 0.22 \text{ OUR FIT}$ Error includes scale factor of 1.2.

$2.5 \pm 0.4 \text{ OUR AVERAGE}$

$2.69 \pm 0.46$ 1 HAYES 71 CNTR 8.3,9,8.7 Cγ → $\mu^+\mu^- X$

$2.17 \pm 0.60$ 1 EARLES 70 CNTR 6.0 γC → $\mu^+\mu^- X$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$2.87 \pm 0.20 \pm 0.14$ 2 ACHASOV 01G SND e⁺ e⁻ → $\mu^+\mu^-$

$3.30 \pm 0.45 \pm 0.32$ 3 ACHASOV 99C SND e⁺ e⁻ → $\mu^+\mu^-$

$4.83 \pm 1.02$ 4 VASSERMAN 81 OLYA e⁺ e⁻ → $\mu^+\mu^-$

$2.87 \pm 1.98$ 4 AUGUSTIN 73 OSPK e⁺ e⁻ → $\mu^+\mu^-$

¹Neglecting interference between resonance and continuum.

²Using $B(\phi \to e^+e^-) = (2.91 \pm 0.07) \times 10^{-4}$.

³Using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$.

⁴Recalculated by us using $B(\phi \to e^+e^-) = (2.99 \pm 0.08) \times 10^{-4}$.

$$ \frac{[\Gamma(\eta e^+ e^-)]}{\Gamma_{\eta e^+ e^-}} \quad \frac{\Gamma_{\eta e^+ e^-}}{\Gamma_{\eta e^+ e^-}} \quad \frac{\Gamma_{\eta e^+ e^-}}{\Gamma_{\eta e^+ e^-}} \quad \Gamma_{\eta e^+ e^-} $$

$\text{VALUE} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$1.08 \pm 0.04 \text{ OUR AVERAGE}$

$1.075 \pm 0.007 \pm 0.038$ 30k 1 BABUSCI 15 KLOE 1.02 e⁺ e⁻ → $\eta e^+ e^-$

$1.19 \pm 0.19 \pm 0.12$ 213 3 ACHASOV 01B SND e⁺ e⁻ → $\eta e^+ e^-$

$1.14 \pm 0.10 \pm 0.06$ 355 AKHMETSHIN 01 CMD2 e⁺ e⁻ → $\eta e^+ e^-$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$1.13 \pm 0.14 \pm 0.07$ 183 4 AKHMETSHIN 01 CMD2 e⁺ e⁻ → $\eta e^+ e^-$

$1.21 \pm 0.14 \pm 0.09$ 130 5 AKHMETSHIN 01 CMD2 e⁺ e⁻ → $\eta e^+ e^-$

$1.04 \pm 0.20 \pm 0.08$ 42 6 AKHMETSHIN 01 CMD2 e⁺ e⁻ → $\eta e^+ e^-$

$1.3 \pm 0.8$ 7 GOLUBEV 85 ND e⁺ e⁻ → $\eta e^+ e^-$

¹Using $B(\eta \to 3\pi^0) = (32.57 \pm 0.23)\%$ from PDG 12.

²Using $B(\eta \to \gamma\gamma) = (39.25 \pm 0.32)\%$, $B(\phi \to \eta\gamma) = (1.26 \pm 0.06)\%$, and $B(\phi \to e^+e^-) = (3.00 \pm 0.06) \times 10^{-4}$.

³The average of the branching ratios separately obtained from the $\eta \to \gamma\gamma$, $3\pi^0$, $\pi^+\pi^-\pi^0$ decays.

⁴From $\eta \to \gamma\gamma$ decays and using $B(\eta \to \gamma\gamma) = (39.33 \pm 0.25) \times 10^{-2}$, $B(\eta \to \pi^+\pi^-\gamma) = (4.75 \pm 11) \times 10^{-2}$, and $B(\phi \to \eta\gamma) = (1.29 \pm 0.033) \times 10^{-2}$.

⁵From $\eta \to 3\pi^0$ decays and using $B(\eta \to \gamma\gamma) = (98.798 \pm 0.033) \times 10^{-2}$, $B(\eta \to 3\pi^0) = (32.24 \pm 0.29) \times 10^{-2}$, $B(\eta \to \pi^+\pi^-\gamma) = (4.75 \pm 0.11) \times 10^{-2}$, and $B(\phi \to \eta\gamma) = (1.297 \pm 0.033) \times 10^{-2}$.

⁶From $\eta \to \pi^+\pi^-\pi^0$ decays and using $B(\pi^0 \to \gamma\gamma) = (98.798 \pm 0.033) \times 10^{-2}$, $B(\pi^0 \to e^+e^-) = (1.198 \pm 0.032) \times 10^{-2}$, $B(\eta \to \pi^+\pi^-\pi^0) = (23.0 \pm 0.4) \times 10^{-2}$, $B(\phi \to \eta\gamma) = (1.297 \pm 0.033) \times 10^{-2}$.
$\Gamma(\pi^+\pi^-)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-4}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>0.71 ± 0.11 ± 0.09</td><td>1 ACHASOV</td><td>00c</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>0.65 <sup>+0.38</sup><sub>-0.29</sub></td><td>1 GOLUBEV</td><td>86</td><td>ND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>2.01 <sup>+1.07</sup><sub>-0.84</sub></td><td>1 VASSERMAN</td><td>81</td><td>Olya</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>&lt;6.6</td><td>95</td><td>BUKIN</td><td>78b</td><td>Olya</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>&lt;2.7</td><td>95</td><td>ALVESLEB...</td><td>72</td><td>CNTR</td><td>6.7 γ C → Cπ<sup>+</sup>π<sup>-</sup></td></tr></table>

¹ Using B($\phi \to e^+e^-$) = (2.99 ± 0.08) × 10⁻⁴.

$\Gamma(\omega\pi^0)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-5}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

4.7 ± 0.5 OUR FIT

<table><tr><td>5.2 <sup>+1.3</sup><sub>-1.1</sub></td><td>1.2 AULCHENKON</td><td>00a</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>π<sup>0</sup></td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>4.4 ± 0.6</td><td>3 AMBROSINO</td><td>08g</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>2π<sup>0</sup>, 2π<sup>0</sup>γ</td></tr><tr><td>~ 5.4</td><td>4 ACHASOV</td><td>00e</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>5.5 <sup>+1.6</sup><sub>-1.4</sub> ± 0.3</td><td>2.5 AULCHENKON</td><td>00a</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>π<sup>0</sup></td></tr><tr><td>4.8 <sup>+1.9</sup><sub>-1.7</sub> ± 0.8</td><td>4 ACHASOV</td><td>99</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>π<sup>0</sup></td></tr></table>

¹ Using the 1996 and 1998 data.

² (2.3 ± 0.3)% correction for other decay modes of the $\omega(782)$ applied.

³ Not independent of the corresponding $\Gamma(\omega^0) \times \Gamma(e^+e^-) / \Gamma^2(\text{total})$.

⁴ Using the 1996 data.

⁵ Using the 1998 data.

$\Gamma(\omega^0)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-4}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

<0.05

$\Gamma(\rho^0)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-4}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

< 0.12

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>&lt; 7</td><td>90</td><td>AKHMETSHIN 97c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>&lt;200</td><td>84</td><td>LINDSEY</td><td>66</td><td>HBC</td><td>2.1–2.7 K<sup>-</sup> p → Λπ<sup>+</sup>π<sup>-</sup> neutrals</td></tr></table>

¹Supersedes AKHMETSHIN 97c.

$\Gamma(\pi^+\pi^-)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-4}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

0.41 ± 0.12 ± 0.04

<table><tr><td>&lt; 0.3</td><td>90</td><td>2 AKHMETSHIN 97c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>&lt;600</td><td>90</td><td>KALBFLEISCH 75</td><td>HBC</td><td>2.18 K<sup>-</sup> p → Λπ<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>&lt; 70</td><td>90</td><td>COSME</td><td>74</td><td>OSPK</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>&lt;400</td><td>90</td><td>LINDSEY</td><td>65</td><td>HBC</td><td>2.1–2.7 K<sup>-</sup> p → Λπ<sup>+</sup>π<sup>-</sup> neutrals</td></tr></table>

¹ For $E_\gamma > 20$ MeV and assuming that $B(\phi(1020) \to f_0(980)\gamma)$ is negligible. Supersedes AKHMETSHIN 97c.

² For $E_\gamma > 20$ MeV and assuming that $B(\phi(1020) \to f_0(980)\gamma)$ is negligible.

$\Gamma(f_0(980)\gamma)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-4}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

3.22 ± 0.19 OUR FIT

3.21 ± 0.19 OUR AVERAGE

<table><tr><td>3.21 <sup>+0.03</sup><sub>-0.09</sub></td><td>1 AMBROSINO</td><td>07</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>2.90 ± 0.21 ± 1.54</td><td>2 AKHMETSHIN 99c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ, π<sup>0</sup>π<sup>0</sup>γ</td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>4.47 ± 0.21</td><td>2438</td><td>3 ALOISIO</td><td>02d</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>3.5 ± 0.3 <sup>+1.3</sup><sub>-0.5</sub></td><td>419</td><td>4,5 ACHASOV</td><td>00h</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>1.93 ± 0.46 ± 0.50</td><td>27188</td><td>6 AKHMETSHIN 99b</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>3.05 ± 0.25 ± 0.72</td><td>268</td><td>7 AKHMETSHIN 99c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>1.5 ± 0.5</td><td>268</td><td>8 AKHMETSHIN 99c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>3.42 ± 0.30 ± 0.36</td><td>164</td><td>4 ACHASOV</td><td>98i</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → 5γ</td></tr><tr><td>&lt; 1</td><td>90</td><td>9 AKHMETSHIN 97c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>&lt; 7</td><td>90</td><td>10 AKHMETSHIN 97c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>γ</td></tr><tr><td>&lt; 20</td><td>90</td><td>DRUZHININ</td><td>87</td><td>ND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr></table>

¹ Obtained by the authors taking into account the $\pi^0\pi^0$ decay mode. Includes a component due to $\pi\pi$ production via the $f_0(500)$ meson. Supersedes ALOISIO 02d.

² From the combined fit of the photon spectra in the reactions $e^+e^- \to \pi^+\pi^-$, $\pi^0\pi^0$.

³ From the negative interference with the $f_0(500)$ meson of AITALA 01b using the ACHASOV 89 parameterization for the $f_0(980)$, a Breit-Wigner for the $f_0(500)$, and ACHASOV 01f for the $\rho\pi$ contribution. Superseded by AMBROSINO 07.

⁴ Assuming that the $\pi^0\pi^0\gamma$ final state is completely determined by the $f_0\gamma$ mechanism, neglecting the decay $B(\phi \to K\bar{K}\gamma)$ and using $B(f_0 \to \pi^+\pi^-) = 2B(f_0 \to \pi^0\pi^0)$.

⁵ Using the value $B(\phi \to \eta\gamma) = (1.338 \pm 0.053) \times 10^{-2}$.

⁶ For $E_\gamma > 20$ MeV. Supersedes AKHMETSHIN 97c.

⁷ Neglecting other intermediate mechanisms ($\rho\pi, \sigma\gamma$).

⁸ A narrow pole fit taking into account $f_0(980)$ and $f_0(1200)$ intermediate mechanisms.

⁹ For destructive interference with the Bremsstrahlung process.

¹⁰ For constructive interference with the Bremsstrahlung process.

$\Gamma(f_0(980)\gamma)/\Gamma(\eta\gamma)$

$\Gamma_{\text{total}}$ (units $10^{-2}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

2.48 ± 0.15 OUR FIT

<table><tr><td>2.6 ± 0.2 <sup>+0.8</sup><sub>-0.3</sub></td><td>419</td><td>1 ACHASOV</td><td>00H</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr></table>

¹ Assuming that the $\pi^0\pi^0\gamma$ final state is completely determined by the $f_0\gamma$ mechanism, neglecting the decay $B(\phi \to K\bar{K}\gamma)$ and using $B(f_0 \to \pi^+\pi^-) = 2B(f_0 \to \pi^0\pi^0)$.

$\Gamma(\pi^0\pi^0\gamma)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-4}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

1.07 ± 0.06 OUR AVERAGE

<table><tr><td>1.07 <sup>+0.01</sup><sub>-0.03</sub></td><td>1 AMBROSINO</td><td>07</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>1.08 ± 0.17 ± 0.09</td><td>268</td><td>AKHMETSHIN 99c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>1.09 ± 0.03 ± 0.05</td><td>2438</td><td>ALOISIO</td><td>02d</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>1.158 ± 0.093 ± 0.052</td><td>419</td><td>2,3 ACHASOV</td><td>00H</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>&lt;10</td><td>90</td><td>DRUZHININ</td><td>87</td><td>ND</td><td>e<sup>+</sup>e<sup>-</sup> → 5γ</td></tr></table>

¹Supersedes ALOISIO 02d.

² Using the value $B(\phi \to \eta\gamma) = (1.338 \pm 0.053) \times 10^{-2}$.

³ Supersedes ACHASOV 98i. Excluding $\omega\pi^0$.

$\Gamma(\pi^0\pi^0\gamma)/\Gamma(\eta\gamma)$

$\Gamma_{\text{total}}$ (units $10^{-2}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

<table><tr><td>0.86 ± 0.04 OUR FIT</td><td>1 ACHASOV</td><td>00H</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr><tr><td>0.865 ± 0.070 ± 0.017</td><td>419</td><td>1 ACHASOV</td><td>00H</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>π<sup>0</sup>γ</td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>0.90 ± 0.08 ± 0.07</td><td>164</td><td>AKHMETSHIN 98i</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → 5γ</td></tr></table>

¹Supersedes ACHASOV 98i. Excluding $\omega\pi^0$.

$\Gamma(\pi^+\pi^-\pi^+\pi^-)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-6}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

<table><tr><td>6.5 ± 2.7 ± 1.6</td><td>6.8k</td><td>1 AKHMETSHIN 17</td><td>CMD3</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>3.93 ± 1.74 ± 2.14</td><td>3.3k</td><td>AKHMETSHIN 00e</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>&lt; 870</td><td>90</td><td>CORDIER</td><td>79</td><td>WIRE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr></table>

¹ Using the cross section at the $\phi$ meson peak $\sigma(\phi) = 4172 \pm 42$ nb, the nonresonant cross section $\sigma(0) = 1.263 \pm 0.027$ nb and Re(Z) = 0.146 ± 0.030, Im(Z) = -0.002 ± 0.024 for the complex amplitude of the $\phi \to \pi^+\pi^-\pi^+\pi^-$ transition.

$\Gamma(\pi^+\pi^+\pi^-\pi^-)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-6}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

<table><tr><td>&lt; 4.6</td><td>90</td><td>AKHMETSHIN 00e</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr><tr><td>&lt;150</td><td>95</td><td>BARKOV</td><td>88</td><td>CMD</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td></tr></table>

$\Gamma(\pi^0 e^+e^-)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-5}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

1.33 <sup>+0.07</sup><sub>-0.10</sub> OUR AVERAGE

<table><tr><td>1.35 ± 0.05 <sup>+0.05</sup><sub>-0.10</sub></td><td>9.5k</td><td>1 ANASTASI</td><td>16b</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>e<sup>+</sup>e<sup>-</sup></td></tr><tr><td>1.01 ± 0.28 ± 0.29</td><td>52</td><td>2 ACHASOV</td><td>02d</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>e<sup>+</sup>e<sup>-</sup></td></tr><tr><td>1.22 ± 0.34 ± 0.21</td><td>46</td><td>3 AKHMETSHIN 01c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>e<sup>+</sup>e<sup>-</sup></td></tr><tr><td>&lt;12</td><td>90</td><td>DOLINSKY</td><td>88</td><td>ND</td><td>e<sup>+</sup>e<sup>-</sup> → π<sup>0</sup>e<sup>+</sup>e<sup>-</sup></td></tr></table>

¹ Using $B(\pi^0 \to \gamma\gamma)$ from the 2014 Edition of this Review (PDG 14).

² Using other branching ratios from the 2000 Edition of this Review (PDG 00).

³ Using $B(\pi^0 \to \gamma\gamma) = 0.98798 \pm 0.00032$, $B(\phi \to \eta\gamma) = (1.297 \pm 0.033) \times 10^{-2}$, and $B(\eta \to \pi^+\pi^-\gamma) = (4.75 \pm 0.11) \times 10^{-2}$.

$\Gamma(\pi^0\eta\gamma)/\Gamma_{\text{total}}$

$\Gamma_{\text{total}}$ (units $10^{-5}$) $\quad \text{CL%}$ $\quad \text{DOCUMENT ID}$ $\quad \text{TECN}$ $\quad \text{COMMENT}$

7.27 ± 0.30 OUR AVERAGE

<table><tr><td>7.06 ± 0.22</td><td>16.9k</td><td>1 AMBROSINO</td><td>09f</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → \eta\pi<sup>0</sup>γ</td></tr><tr><td>8.51 ± 0.51 ± 0.57</td><td>607</td><td>2 ALOISIO</td><td>02c</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → \eta\pi<sup>0</sup>γ</td></tr><tr><td>7.96 ± 0.60 ± 0.40</td><td>197</td><td>3 ALOISIO</td><td>02c</td><td>KLOE</td><td>e<sup>+</sup>e<sup>-</sup> → \eta\pi<sup>0</sup>γ</td></tr><tr><td>8.8 ± 1.4 ± 0.9</td><td>36</td><td>4 ACHASOV</td><td>00f</td><td>SND</td><td>e<sup>+</sup>e<sup>-</sup> → \eta\pi<sup>0</sup>γ</td></tr><tr><td>9.0 ± 2.4 ± 1.0</td><td>80</td><td>AKHMETSHIN 99c</td><td>CMD2</td><td>e<sup>+</sup>e<sup>-</sup> → \eta\pi<sup>0</sup>γ</td></tr><tr><td>&lt;250</td><td>90</td><td>DOLINSKY</td><td>91</td><td>ND</td><td>e<sup>+</sup>e<sup>-</sup> → \eta\pi<sup>0</sup>γ</td></tr></table>

¹ Combined results of $\eta \to \gamma\gamma$ and $\eta \to \pi^+\pi^-\pi^0$ decay modes measurements.
# Meson Particle Listings

$\phi(1020)$

² From the decay mode $\eta \to \gamma\gamma$.

³ From the decay mode $\eta \to \pi^+\pi^-\pi^0$.

⁴ Supersedes ACHASOV 98b.

⁵ Using $B(\phi \to \eta\gamma) = (1.304 \pm 0.025)\%$, $B(\eta \to 3\pi^0) = (32.56 \pm 0.23)\%$, and $B(\eta \to \gamma\gamma) = (39.31 \pm 0.20)\%$.

⁶ Using $B(\phi \to \eta\gamma) = (1.304 \pm 0.025)\%$, $B(\eta \to 3\pi^0) = (32.56 \pm 0.23)\%$, and $B(\eta \to \pi^+\pi^-\pi^0) = (22.73 \pm 0.28)\%$.

<figure><img src="image_448.png" /></figure>

$$ \Gamma(\phi_0(980)\gamma)/\Gamma_{\text{total}} \qquad \Gamma_{22}/\Gamma $$

$\text{VALUE (units } 10^{-5}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### 7.6±0.6 OUR FIT

### 7.6±0.6 OUR AVERAGE

$7.4 \pm 0.7$

$8.8 \pm 1.7$

$1 \text{ ALOISIO} \quad 02c \text{ KLOE} \quad e^+ e^- \to \eta \pi^0 \gamma$

$2 \text{ ACHASOV} \quad 00f \quad \text{SND} \quad e^+ e^- \to \eta \pi^0 \gamma$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$11 \pm 2$

$500 \quad 90$

$3 \text{ GOKALP} \quad 02 \quad \text{RVUE} \quad e^+ e^- \to \eta \pi^0 \gamma$

$4 \text{ DOLINSKY} \quad 91 \quad \text{ND} \quad e^+ e^- \to \pi^0 \eta \gamma$

¹ Using $M_{a_0(980)}=984.8$ MeV and assuming $a_0(980)\gamma$ dominance.

² Assuming $a_0(980)\gamma$ dominance in the $\eta\pi^0\gamma$ final state.

³ Using data of ACHASOV 00F.

$$ \Gamma(\phi_0(980)\gamma)/\Gamma(\phi_0(980)\gamma) \qquad \Gamma_{16}/\Gamma_{22} $$

$\text{VALUE} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### 6.1±0.6

$1 \text{ ALOISIO} \quad 02c \text{ KLOE} \quad e^+ e^- \to \eta \pi^0 \gamma$

¹ Using results of ALOISIO 02D and assuming that $f_0(980)$ decays into $\pi\pi$ only and $a_0(980)$ into $\eta\pi$ only.

$$ \Gamma(\kappa^0\bar{\kappa}^0\gamma)/\Gamma_{\text{total}} \qquad \Gamma_{23}/\Gamma $$

$\text{VALUE} \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$$ \Gamma(\eta'(958)\gamma)/\Gamma_{\text{total}} \qquad \Gamma_{24}/\Gamma $$

$\text{VALUE (units } 10^{-5}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### 6.21±0.20 OUR FIT

### 6.21±0.29 OUR AVERAGE

$6.21 \pm 0.27 \pm 0.11 \quad 3407 \quad 1 \text{ AMBROSINO} \quad 07A \text{ KLOE} \quad 1.02 e^+ e^- \to \pi^+ \pi^- \gamma$

$6.7 \pm 2.8 \pm 0.8 \quad 12 \quad 2 \text{ AULCHENKO} \quad 03B \quad \text{SND} \quad e^+ e^- \to \eta' \gamma$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$6.7 \pm 5.0 \pm 1.5 \quad 7 \quad \text{AULCHENKO} \quad 03B \quad \text{SND} \quad e^+ e^- \to \gamma\gamma$

$6.10 \pm 0.61 \pm 0.43 \quad 120 \quad 3 \text{ ALOISIO} \quad 02E \text{ KLOE} \quad 1.02 e^+ e^- \to \pi^+ \pi^- \gamma$

$8.2 \pm 2.1 \pm 1.1 \quad 21 \quad 4 \text{ AKHMETSHIN} \quad 00B \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

$4.9 \pm 2.2 \pm 0.6 \quad 9 \quad 5 \text{ AKHMETSHIN} \quad 00F \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \pi^+ \pi^- \ge 2\gamma$

$6.4 \pm 1.6 \quad 30 \quad 6 \text{ AKHMETSHIN} \quad 00F \quad \text{CMD2} \quad e^+ e^- \to \eta'(958)\gamma$

$6.7 \pm 3.4 \pm 1.0 \quad 5 \quad 7 \text{ AULCHENKO} \quad 99 \quad \text{SND} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

$<11 \quad 90 \quad 7 \text{ AULCHENKO} \quad 98 \quad \text{SND} \quad e^+ e^- \to \gamma\gamma$

$12 \pm 7 \pm 2 \quad 6 \quad 4 \text{ AKHMETSHIN} \quad 97B \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

¹ AMBROSINO 07A reports $[\Gamma(\phi(1020) \to \eta'(958)\gamma)/\Gamma_{\text{total}}] / [B(\phi(1020) \to \eta\gamma)] = (4.77 \pm 0.09 \pm 0.19) \times 10^{-3}$ which we multiply by our best value $B(\phi(1020) \to \eta\gamma) = (1.301 \pm 0.024) \times 10^{-2}$. Our first error is their experiment's error and our second error is the systematic error from using our best value.

² Averaging AULCHENKO 03B with AULCHENKO 99.

³ Using $B(\phi \to \eta\gamma) = (1.297 \pm 0.033)\%$.

⁴ Using the value $B(\phi \to \eta\gamma) = (1.26 \pm 0.06) \times 10^{-2}$.

⁵ Using $B(\phi \to \kappa^0\bar{\kappa}^0) = (33.8 \pm 0.6)\%$.

⁶ Averaging AKHMETSHIN 00B with AKHMETSHIN 00F.

⁷ Using the value $B(\eta' \to \eta\pi^+\pi^-) = (43.7 \pm 1.5) \times 10^{-2}$ and $B(\eta \to \gamma\gamma) = (39.25 \pm 0.31) \times 10^{-2}$.

$$ \Gamma(\eta'(958)\gamma)/\Gamma(\kappa^0\bar{\kappa}^0) \qquad \Gamma_{24}/\Gamma_{25} $$

$\text{VALUE (units } 10^{-4}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### 1.83±0.06 OUR FIT

$1.46 \pm 0.64 \pm 0.18 \quad 9 \quad 1 \text{ AKHMETSHIN} \quad 00F \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \pi^+ \pi^- \ge 2\gamma$

¹ Using various branching ratios of $\kappa_S^0, \kappa_L^0, \eta, \eta'$ from the 2000 edition (The European Physical Journal C15 1 (2000)) of this Review.

$$ \Gamma(\eta'(958)\gamma)/\Gamma(\eta\gamma) \qquad \Gamma_{24}/\Gamma_{25} $$

$\text{VALUE (units } 10^{-3}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### 4.77±0.15 OUR FIT

### 4.78±0.20 OUR AVERAGE

$4.77 \pm 0.09 \pm 0.19 \quad 3407 \quad \text{AMBROSINO} \quad 07A \text{ KLOE} \quad 1.02 e^+ e^- \to \pi^+ \pi^- \gamma$

$4.70 \pm 0.47 \pm 0.31 \quad 120 \quad 1 \text{ ALOISIO} \quad 02E \text{ KLOE} \quad 1.02 e^+ e^- \to \pi^+ \pi^- \gamma$

$6.5 \pm 1.7 \pm 0.8 \quad 21 \quad \text{AKHMETSHIN} \quad 00B \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$9.5 \pm 5.2 \pm 1.4 \quad 6 \quad 2 \text{ AKHMETSHIN} \quad 97B \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

¹ From the decay mode $\eta' \to \eta\pi^+\pi^-$, $\eta \to \gamma\gamma$.

² Superseded by AKHMETSHIN 00B.

$$ \Gamma(\eta\pi^0\pi^0\gamma)/\Gamma_{\text{total}} \qquad \Gamma_{25}/\Gamma $$

$\text{VALUE (units } 10^{-5}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### 1.43±0.45±0.14

$1.43 \pm 0.45 \pm 0.14 \quad 27188 \quad 1 \text{ AKHMETSHIN} \quad 99B \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$2.3 \pm 1.0 \quad 824 \pm 33 \quad 2 \text{ AKHMETSHIN} \quad 97C \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma$

¹ For $E_\gamma > 20$ MeV. Supersedes AKHMETSHIN 97C.

² For $E_\gamma > 20$ MeV.

$$ \Gamma(\rho\gamma\gamma)/\Gamma_{\text{total}} \qquad \Gamma_{27}/\Gamma $$

$\text{VALUE (units } 10^{-4}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$<1.2 \quad 90 \quad \text{AULCHENKO} \quad 08 \quad \text{CMD2} \quad \phi \to \pi^+\pi^-\gamma\gamma$

$$ \Gamma(\eta\pi^+\pi^-)/\Gamma_{\text{total}} \qquad \Gamma_{28}/\Gamma $$

$\text{VALUE (units } 10^{-5}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

• • • We do not use the following data for averages, fits, limits, etc. • • •

$<6.1 \quad 90 \quad \text{AULCHENKO} \quad 08 \quad \text{CMD2} \quad \phi \to \eta\pi^+\pi^-$

$<30 \quad 90 \quad \text{AKHMETSHIN} \quad 98 \quad \text{CMD2} \quad e^+ e^- \to \pi^+ \pi^- \gamma\gamma$

$$ \Gamma(\eta\mu^+\mu^-)/\Gamma_{\text{total}} \qquad \Gamma_{29}/\Gamma $$

$\text{VALUE (units } 10^{-6}) \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

### $\Gamma(\eta U \to \eta e^+ e^-)/\Gamma_{\text{total}}$

$\text{VALUE} \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

¹ For a narrow vector U with mass between 5 and 470 MeV, from the combined analysis of $\eta \to \pi^+\pi^-\pi^0$ and $\eta \to \pi^0\pi^0\pi^0$ from ARCHILLI 12. Measured 90% CL limits as a function of $m_U$ range from $2.2 \times 10^{-8}$ to $10^{-6}$.

$$ \Gamma(\text{invisible})/\Gamma(\kappa^+\bar{\kappa}^-) \qquad \Gamma_{31}/\Gamma $$

$\text{VALUE} \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$<3.4 \times 10^{-4} \quad 90 \quad \text{ABLIKIM} \quad 18\text{S} \quad \text{BES3} \quad J/\psi \to \phi\eta \to \phi\pi^+\pi^-\pi^0$

### Lepton Family number (LF) violating modes

$$ \Gamma(e^\pm\mu^\pm)/\Gamma_{\text{total}} \qquad \Gamma_{32}/\Gamma $$

$\text{VALUE} \quad \text{CL\%} \quad \text{EVTS} \quad \text{DOCUMENT ID} \quad \text{TECN} \quad \text{COMMENT}$

$<2 \times 10^{-6} \quad 90 \quad \text{ACHASOV} \quad 10A \quad \text{SND} \quad e^+ e^- \to e^\pm\mu^\pm$
$\pi^+\pi^-\pi^0 / \rho\pi$ AMPLITUDE RATIO $a_1$ IN DECAY OF $\phi \to \pi^+\pi^-\pi^0$

NIECKNIG 12 describes final-state interactions between the three pions in a dispersive framework using data on the $\pi\pi$ P-wave scattering phase shift.

<table><thead><tr><th>VALUE (units 10<sup>-2</sup>)</th><th>CL%</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td colspan="6"><strong>9.1&plusmn;1.2 OUR AVERAGE</strong></td></tr><tr><td>10.1&plusmn;4.4&plusmn;1.7</td><td>80k</td><td></td><td>1 AKHMETSHIN 06</td><td>CMD2</td><td>1.017&minus;1.021 e<sup>+</sup>e<sup>&minus;</sup> &rarr; &pi;<sup>+</sup>&pi;<sup>&minus;</sup>&pi;<sup>0</sup></td></tr><tr><td>9.0&plusmn;1.1&plusmn;0.6</td><td>1.98M</td><td></td><td>2,3 ALOISIO 03</td><td>KLOE</td><td>1.02 e<sup>+</sup>e<sup>&minus;</sup> &rarr; &pi;<sup>+</sup>&pi;<sup>&minus;</sup>&pi;<sup>0</sup></td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •
-6 &lt; $a_1$ &lt; 6
-9 &lt; $a_1$ &lt; 11
-6 &lt; $a_1$ &lt; 19
-9 &lt; $a_1$ &lt; 90
-9 &lt; $a_1$ &lt; 98
-1,4 AKHMETSHIN 98 CMD2 e<sup>+</sup>e<sup>&minus;</sup> &rarr; $\pi^+\pi^-\pi^0$

¹ Dalitz plot analysis taking into account interference between the contact and $\rho\pi$ amplitudes.

² From a fit without limitations on charged and neutral $\rho$ masses and widths.

³ Recalculated by us to match the notations of AKHMETSHIN 98.

⁴ Assuming zero phase for the contact term.

PARAMETER $\beta$ IN $\phi \to Pe^+e^-$ DECAYS

In the one-pole approximation the electromagnetic transition form factor for $\phi \to Pe^+e^-$ ($P=\pi,\pi$) is given as a function of the $e^+e^-$ invariant mass squared, $q^2$, by the expression:

$|F(q^2)|^2 = (1 - q^2/\Lambda^2)^2$, where vector meson dominance predicts parameter $\Lambda \approx 0.770$ GeV ($\Lambda^{-2} \approx 1.687$ GeV$^{-2}$). The slope of this form factor, $\beta = dF/dq^2$ ($q^2=0$), equals $\Lambda^{-2}$ in this approximation.

The measurements below obtain $\beta$ in the one-pole approximation.

PARAMETER $\beta$ IN $\phi \to \pi^0 e^+ e^-$ DECAY

<table><thead><tr><th>VALUE (GeV<sup>-2</sup>)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>2.02&plusmn;0.11</td><td>9.5k</td><td>1 ANASTASI 16b</td><td>KLOE</td><td>1.02 e<sup>+</sup>e<sup>&minus;</sup> &rarr; $\pi^0 e^+ e^-$</td></tr></tbody></table>

¹ The error combines statistical and systematic uncertainties.

PARAMETER $\beta$ IN $\phi \to \eta^+ e^-$ DECAY

<table><thead><tr><th>VALUE (GeV<sup>-2</sup>)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td colspan="5"><strong>1.29&plusmn;0.13 OUR AVERAGE</strong></td></tr><tr><td>1.28&plusmn;0.10<sup>+0.09</sup><sub>-0.08</sub></td><td>30k</td><td>BABUSCI</td><td>15</td><td>KLOE</td><td>1.02 e<sup>+</sup>e<sup>&minus;</sup> &rarr; $\eta^+ e^+ e^-$</td></tr><tr><td>3.8 &plusmn; 1.8</td><td>213</td><td>1 ACHASOV 01b</td><td>SND</td><td>1.02 e<sup>+</sup>e<sup>&minus;</sup> &rarr; $\eta^+ e^+ e^-$</td></tr></tbody></table>

¹ The uncertainty is statistical only. The systematic one is negligible, in comparison.

$\phi(1020)$ REFERENCES

<table><tbody><tr><td>LEES</td><td>21B</td><td>PR D104 112003</td><td>J.P. Lees et al.</td><td>(BABAR Collab.)</td></tr><tr><td>ALBRECHT</td><td>20</td><td>EPJ C80 455</td><td>M. Albrecht et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>HOID</td><td>20</td><td>EPJ C80 988</td><td>B.-L. Hoid, M. Hofeicher, B. Kubis</td><td>(BONN, BERN)</td></tr><tr><td>AAIJ</td><td>19H</td><td>JHEP 1904 063</td><td>R. Aaij et al.</td><td>(LHCb Collab.)</td></tr><tr><td>HOFERICHT...</td><td>19</td><td>JHEP 1908 137</td><td>M. Hofeicher, B.-L. Hoid, B. Kubis</td><td>(WASH, BONN)</td></tr><tr><td>ABLIKIM</td><td>18S</td><td>PR D98 032001</td><td>(BESHI Collab.)</td><td></td></tr><tr><td>AOUDIE</td><td>18</td><td>PR D98 056021</td><td>R.T. Aoude et al.</td><td></td></tr><tr><td>KOZYREV</td><td>18</td><td>PL B779 64</td><td>E.A. Kozrev et al.</td><td>(CMD-3 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>17</td><td>PL B768 345</td><td>R.R. Akhmetshin et al.</td><td>(CMD-3 Collab.)</td></tr><tr><td>ACHASOV</td><td>16A</td><td>PR D93 092001</td><td>M.N. Achasov et al.</td><td>(SND Collab.)</td></tr><tr><td>ANASTASI</td><td>15B</td><td>PL B757 362</td><td>A. Anastasi et al.</td><td>(KLOE-2 Collab.)</td></tr><tr><td>KOZYREV</td><td>16</td><td>PL B760 314</td><td>E.A. Kozrev et al.</td><td>(CMD-3 Collab.)</td></tr><tr><td>BABUSCI</td><td>15</td><td>PL B742 1</td><td>D. Babusci et al.</td><td>(KLOE-2 Collab.)</td></tr><tr><td>PDG</td><td>15</td><td>RPP 2015 at pdg.lbf.gov</td><td></td><td>(PDG Collab.)</td></tr><tr><td>LEES</td><td>14H</td><td>PR D89 092002</td><td>J.P. Lees et al.</td><td>(BABAR Collab.)</td></tr><tr><td>PDG</td><td>14</td><td>CP C38 070001</td><td>K. Olive et al.</td><td>(PDG Collab.)</td></tr><tr><td>BABUSCI</td><td>13B</td><td>PL B720 111</td><td>D. Babusci et al.</td><td>(KLOE-2 Collab.)</td></tr><tr><td>BENAYOUN</td><td>13B</td><td>EPJ C73 2453</td><td>M. Benayoun, P. David, L. DelBuono (PARIN, BERLIN+)</td><td></td></tr><tr><td>LEES</td><td>13F</td><td>PR D87 052010</td><td>J.P. Lees et al.</td><td>(BABAR Collab.)</td></tr><tr><td>LEES</td><td>13Q</td><td>PR D88 032013</td><td>J.P. Lees et al.</td><td>(BABAR Collab.)</td></tr><tr><td>ARCHILLI</td><td>12</td><td>PL B706 251</td><td>F. Archilli et al.</td><td>(KLOE-2 Collab.)</td></tr><tr><td>BENAYOUN</td><td>12</td><td>EPJ C72 1848</td><td>M. Benayoun et al.</td><td></td></tr><tr><td>NEICKNIG</td><td>12</td><td>PR D72 010201</td><td>F. Niecknig, B. Kubis, S.P. Schneider (BONN)</td><td></td></tr><tr><td>PDG</td><td>12</td><td>PR D86 010001</td><td>J. Beringer et al.</td><td>(PDG Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>11</td><td>PL B695 412</td><td>R.R. Akhmetshin et al.</td><td>(CMD-2 Collab.)</td></tr><tr><td>ACHASOV</td><td>10A</td><td>PR D81 057102</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>BENAYOUN</td><td>07A</td><td>PL B648 267</td><td>M. Benayoun et al.</td><td></td></tr><tr><td>DUBYNSKIY</td><td>07</td><td>PR D75 113001</td><td>S. Dubyskiy et al.</td><td></td></tr><tr><td>ACHASOV</td><td>06A</td><td>PR D74 014016</td><td>M.N. Achasov et al.</td><td></td></tr><tr><td>AKHMETSHIN</td><td>06</td><td>PL B642 203</td><td>R.R. Akhmetshin et al.</td><td>(SND Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>05</td><td>PL B605 26</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>BENROSINO</td><td>05</td><td>PL B608 199</td><td>F. Ambrosino et al.</td><td>(KLOE Collab.)</td></tr><tr><td>AUBERT, B</td><td>05J</td><td>PR D72 052008</td><td>B. Aubert et al.</td><td>(BABAR Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>04</td><td>PL B578 285</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AUBERT, B</td><td>04N</td><td>PR D70 072004</td><td>B. Aubert et al.</td><td>(BABAR Collab.)</td></tr><tr><td>ALOISIO</td><td>03</td><td>PL B561 55</td><td>A. Aloisio et al.</td><td>(KLOE Collab.)</td></tr><tr><td>AULCHENKO</td><td>03B</td><td>JP E97 24</td><td>V.M. Aulchenko et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>02</td><td>PR D65 032002</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>02D</td><td>JETP 75 449</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td colspan="5">Translated from ZETF 125 28.</td></tr><tr><td colspan="5">Translated from ZETF 75 539.</td></tr></tbody></table>

<table><tbody><tr><td>ALOISIO</td><td>02C</td><td>PL B536 209</td><td>A. Aloisio et al.</td><td>(KLOE Collab.)</td></tr><tr><td>ALOISIO</td><td>02E</td><td>PL B537 21</td><td>A. Aloisio et al.</td><td>(KLOE Collab.)</td></tr><tr><td>ALOISIO</td><td>02E</td><td>PL B541 45</td><td>A. Aloisio et al.</td><td>(KLOE Collab.)</td></tr><tr><td>FISCHBACH</td><td>02</td><td>PL B526 355</td><td>E. Fischbach, A.W. Overhauser, B. Woodahl</td><td></td></tr><tr><td>GOKALP</td><td>02</td><td>JP G28 2783</td><td>A. Gokalp et al.</td><td></td></tr><tr><td>ACHASOV</td><td>01B</td><td>PL B504 275</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>01E</td><td>PR D33 072002</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>01F</td><td>PR D63 094007</td><td>M.N. Achasov, V.V. Gubin</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>01G</td><td>PR B504 275</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>01G</td><td>PR B504 275</td><td>E.M. Aitala et al.</td><td>(FNAL E791 Collab.)</td></tr><tr><td>ACHASOV</td><td>01G</td><td>PR B504 275</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>ACHASOV</td><td>01B</td><td>PL B509 217</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>ACHASOV</td><td>01C</td><td>PL B503 237</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>BENAYOUN</td><td>01</td><td>EPJ C22 503</td><td>M. Benayoun, H.B. O'Connell</td><td></td></tr><tr><td>ACHASOV</td><td>00</td><td>EPJ C12 25</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00B</td><td>JETP 90 17</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00C</td><td>Translated from ZETF 117 22</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00D</td><td>PL B74 188</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00E</td><td>JETP 72 282</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00E</td><td>Translated from ZETF 72 411</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00E</td><td>NP B569 158</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>00H</td><td>PL B485 349</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>00B</td><td>PL B473 337</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>00E</td><td>PL B491 81</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>00F</td><td>PL B494 26</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AULCHENKO</td><td>00A</td><td>JETP 90 927</td><td>V.M. Aulchenko et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td colspan="5">Translated from ZETF 117 1067</td></tr><tr><td>BRAMON</td><td>00</td><td>PL B486 406</td><td>A. Bramon et al.</td><td></td></tr><tr><td>PDG</td><td>00</td><td>PL C15 1</td><td>D.E. Groom et al.</td><td></td></tr><tr><td>ACHASOV</td><td>99</td><td>PL B449 122</td><td>M.N. Achasov et al.</td><td></td></tr><tr><td>ACHASOV</td><td>99C</td><td>PL B456 304</td><td>M.N. Achasov et al.</td><td></td></tr><tr><td>ACHASOV</td><td>99B</td><td>PL B462 371</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>99C</td><td>PL B462 380</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>99D</td><td>PL B466 385</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>Also</td><td>99F</td><td>PL B508 217 (errat.)</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>99F</td><td>PL B460 242</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>AULCHENKO</td><td>99E</td><td>JETP 69 97</td><td>V.M. Aulchenko et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>ACHASOV</td><td>98B</td><td>PL B438 441</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>98F</td><td>JETP 68 573</td><td>M.N. Achasov et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>ACHASOV</td><td>98I</td><td>PL B440 442</td><td>M.N. Akhmetshin et al.</td><td>(CMD-2 Collab.)</td></tr><tr><td>AULCHENKO</td><td>98</td><td>PL B434 426</td><td>V.M. Aulchenko et al.</td><td>(Novosibirsk SND Collab.)</td></tr><tr><td>BARBERIS</td><td>98</td><td>PL B432 199</td><td>D. Barberis et al.</td><td>(Omega Expt.)</td></tr><tr><td>AKHMETSHIN</td><td>97B</td><td>PL B415 445</td><td>R.R. Akhmetshin et al.</td><td>(NOVO, BOST, PITT+)</td></tr><tr><td>AKHMETSHIN</td><td>97C</td><td>PL B415 452</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>BENAYOUN</td><td>96</td><td>M. Benayoun et al.</td><td>M. Benayoun et al.</td><td>(IPNP, NOVO)</td></tr><tr><td>AKHMETSHIN</td><td>95</td><td>PL B364 199</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk CMD-2 Collab.)</td></tr><tr><td>DOLINSKY</td><td>91</td><td>PRPL 202 99</td><td>S.I. Dolinsky et al.</td><td>(NOVO)</td></tr><tr><td>KUHN</td><td>90</td><td>ZPHY C48 445</td><td>J.H. Kuhn et al.</td><td>(MPIM)</td></tr><tr><td>ACHASOV</td><td>89</td><td>NP B315 465</td><td>N.N. Achasov, V.N. Ivanchenko</td><td></td></tr><tr><td>DOLINSKY</td><td>89</td><td>ZPHY C42 511</td><td>S.I. Dolinsky et al.</td><td>(NOVO)</td></tr><tr><td>BARKOV</td><td>88</td><td>SJNP 47 248</td><td>L.M. Barkov et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from YAF 47 393</td></tr><tr><td>DOLINSKY</td><td>88</td><td>SJNP 48 277</td><td>S.I. Dolinsky et al.</td><td>(NOVO)</td></tr><tr><td>DRUZHININ</td><td>87</td><td>Translated from YAF 48 442</td><td>V.P. Druzhinin et al.</td><td>(NOVO)</td></tr><tr><td>ARMSTRONG</td><td>86</td><td>PL 166B 245</td><td>T.A. Armstrong et al.</td><td>(ATHU, BARI, BIRM+)</td></tr><tr><td>ATKINSON</td><td>86</td><td>ZPHY C30 521</td><td>M. Atkinson et al.</td><td>(BONN, CERN, GLAS+)</td></tr><tr><td>BEBEK</td><td>86</td><td>PLR 56 1893</td><td>C. Bebek et al.</td><td>(CLEO Collab.)</td></tr><tr><td>DESPORTE</td><td>86</td><td>PL D6 2519</td><td>T. D. Davison, NADAM+ (TUFTS, ARIZ, FNAL, FSU, CERN+)</td><td></td></tr><tr><td>DIJKSTRA</td><td>86</td><td>ZPHY C31 375</td><td>H. Dijkstra et al.</td><td>(ANIK, BRIS, CERN+)</td></tr><tr><td>FRAME</td><td>86</td><td>NP B276 667</td><td>D. Frame et al.</td><td>(GLAS)</td></tr><tr><td>GOLUBEV</td><td>86</td><td>SJNP 44 409</td><td>V.B. Golubev et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from YAF 44 633</td></tr><tr><td>ALBRECHT</td><td>85D</td><td>PL 153B 343</td><td>H. Albrecht et al.</td><td>(ARGUS Collab.)</td></tr><tr><td>SJNP</td><td>85</td><td>SJNP 41 756</td><td>V.B. Golubev et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from YAF 41 1183</td></tr><tr><td>DRUZHININ</td><td>84</td><td>PL 144B 136</td><td>V.P. Druzhinin et al.</td><td>(NOVO)</td></tr><tr><td>ARMSTRONG</td><td>83B</td><td>NP B224 193</td><td>T.A. Armstrong et al.</td><td>(BARI, BIRM, CERN+)</td></tr><tr><td>BARATE</td><td>83</td><td>PL 121B 449</td><td>R. Barate et al.</td><td>(SACL, LOIC, SHMP, IND)</td></tr><tr><td>KURDADZE</td><td>83C</td><td>JETP 38 366</td><td>L.M. Kurdadze et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from ZETF 38 306</td></tr><tr><td>ARENTON</td><td>82</td><td>PL D24 2241</td><td>M.W. Arenton et al.</td><td>(ANL, ILL)</td></tr><tr><td>PELLINEN</td><td>82</td><td>PS 25 599</td><td>A. P. Pellinen, M. Roos</td><td>(HELS)</td></tr><tr><td>DAUM</td><td>81</td><td>PL 100B 439</td><td>C. Daum et al.</td><td>(AMST, BRIS, CERN, CRAC+)</td></tr><tr><td>IVANOV</td><td>81</td><td>PL 107B 297</td><td>P.M. Ivanov et al.</td><td>(NOVO)</td></tr><tr><td>Also</td><td>81</td><td>Private Comm.</td><td>S.J. Eidelman</td><td>(NOVO)</td></tr><tr><td>VASSERMAN</td><td>81</td><td>PL 99B 62</td><td>I.B. Vasserman et al.</td><td>(NOVO)</td></tr><tr><td>Also</td><td>81</td><td>SJNP 35 240</td><td>L.M. Kurdadze et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from YAF 35 352</td></tr><tr><td>CORDIER</td><td>80</td><td>NP B172 13</td><td>A. Cordier et al.</td><td>(LALO)</td></tr><tr><td>CORDIER</td><td>79</td><td>PL B81 389</td><td>A. Cordier et al.</td><td>(LALO)</td></tr><tr><td>BUKIN</td><td>78B</td><td>SJNP 27 521</td><td>A.D. Bukin et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from YAF 27 985</td></tr><tr><td>BUKIN</td><td>78C</td><td>SJNP 27 516</td><td>A.D. Bukin et al.</td><td>(NOVO)</td></tr><tr><td colspan="5">Translated from YAF 27 976</td></tr><tr><td>COOPER</td><td>78B</td><td>NP B146 1</td><td>A.M. Cooper et al.</td><td>(TATA, CERN, DDEF+)</td></tr><tr><td>LOSTY</td><td>78</td><td>NP B133 38</td><td>M.J. Losty et al.</td><td>(CERN, AMST, NJUM+)</td></tr><tr><td>AKERLOF</td><td>77</td><td>PL R9 861</td><td>C.W. Akerlof et al.</td><td>(FNAL, MICH, PURD)</td></tr><tr><td>ANDREWS</td><td>77</td><td>PL 38 198</td><td>D.E. Andrews et al.</td><td>(ROCH)</td></tr><tr><td>BALDI</td><td>77</td><td>PL 68 381</td><td>R. Baldi et al.</td><td>(GEVA)</td></tr><tr><td>CERRADA</td><td>77B</td><td>PL B126 241</td><td>M. Cerrada et al.</td><td>(AMST, CERN, NJUM+)</td></tr><tr><td>COHEN</td><td>77</td><td>PL D6 259</td><td>D. Cohen et al.</td><td>(ANL)</td></tr><tr><td>LAVEN</td><td>77</td><td>PL B127 43</td><td>H. Laven et al.</td><td>(AACH3, BERL, CERN+IC+)</td></tr><tr><td>LYONS</td><td>77</td><td>NP B125 207</td><td>L. Lyons, A.M. Cooper, A.G. Clark</td><td>(OXF)</td></tr><tr><td>COSME</td><td>76</td><td>PL B63 352</td><td>G. Cosme et al.</td><td>(ORSAY)</td></tr><tr><td>KALBFLEISCH</td><td>76</td><td>PR D13 22</td><td>G.R. Kalbfleisch, R.C. Strand, J.W. Chapman</td><td>(BNL+)</td></tr><tr><td>PARROUR</td><td>76B</td><td>PR B63 357</td><td>G. Parrour et al.</td><td>(ORSAY)</td></tr><tr><td>PARROUR</td><td>76B</td><td>PL B63 362</td><td>G. Parrour et al.</td><td>(ORSAY)</td></tr><tr><td>KALBFLEISCH</td><td>75</td><td>PR D11 987</td><td>G.R. Kalbfleisch, R.C. Strand, J.W. Chapman</td><td>(BNL+)</td></tr><tr><td>AYRES</td><td>74</td><td>PL D2 1463</td><td>D.S. Ayres et al.</td><td>(ANL)</td></tr><tr><td>BESCH</td><td>74</td><td>NP B70 257</td><td>H.J. Besch et al.</td><td>(BONN)</td></tr><tr><td>COSME</td><td>74</td><td>PL B48 155</td><td>G. Cosme et al.</td><td>(ORSAY)</td></tr><tr><td>COSME</td><td>74B</td><td>PL B48 159</td><td>G. Cosme et al.</td><td>(ORSAY)</td></tr><tr><td>DEGROOT</td><td>74</td><td>NP B74 77</td><td>A.J. de Groot et al.</td><td>(AMST, NIJM)</td></tr><tr><td>AUGUSTIN</td><td>73</td><td>PL D30 462</td><td>J.E. Augustin et al.</td><td>(ORSAY)</td></tr><tr><td>BALLAM</td><td>73</td><td>PR D7 3150</td><td>J. Ballam et al.</td><td>(SLAC, LBL)</td></tr><tr><td>BINNE</td><td>73B</td><td>PR D6 2789</td><td>D.M. Binnie et al.</td><td>(LOIC, SHMP)</td></tr><tr><td>AGUILAR...</td><td>72</td><td>PL D6 29</td><td>M. Aguilar-Bentez et al.</td><td>(BNL)</td></tr><tr><td>ALVENSLEB...</td><td>72</td><td>PR D8 66</td><td>H. Alvensleben et al.</td><td>(MIT, DESY)</td></tr><tr><td>BORENSTEIN</td><td>72</td><td>PL R6 1559</td><td>S.R. Borenstein et al.</td><td>(BNL, MICH)</td></tr><tr><td>COLLEY</td><td>72</td><td>NP B50 1</td><td>D.C. Colley et al.</td><td>(BIRM, GLAS)</td></tr><tr><td>BALAKIN</td><td>71</td><td>PL 34B 328</td><td>V.E. Balakin et al.</td><td>(NOVO)</td></tr><tr><td>CHATELUS</td><td>71</td><td>Thesis LAL 1247</td><td>Y. Chelatus</td><td>(STRBB)</td></tr><tr><td>Also</td><td>71</td><td>PL 32B 416</td><td>J.C. Bizot et al.</td><td>(ORSAY)</td></tr><tr><td>HAYES</td><td>71</td><td>PR D4 899</td><td>S. Hayes et al.</td><td>(CORN)</td></tr><tr><td>STOTTLE...</td><td>71</td><td>Thesis ORO 2504 170</td><td>A.R. Stottleymer</td><td>(UMD)</td></tr><tr><td>BIZOT</td><td>70</td><td>PL 32B 416</td><td>J.C. Bizot et al.</td><td>(ORSAY)</td></tr><tr><td colspan="5">Translated from ZETF 125 28.</td></tr><tr><td>EARLES</td><td>70</td><td>PR 25 1312</td><td>D.R. Earles et al.</td><td>(NEAS)</td></tr><tr><td>LINDSEY</td><td>66</td><td>PR 147 913</td><td>J.S. Lindsey, G. Smith</td><td>(LRL)</td></tr></tbody></table>
# Meson Particle Listings

## $\phi(1020)$, $h_1(1170)$, $b_1(1235)$

LONDON 66 PR 143 1034

BADIER 65B PL 17 337

LINDSEY 65 PRL 15 221

LINDSEY 65 data included in LINDSEY 66.

SCHLEIN 63 PRL 10 368

G.W. London et al.

J. Badier et al.

J.S. Lindsey, G.A. Smith

P.E. Schlein et al.

(BNL, SYRA) IGJPC
(EPOL, SACL, AMST)

(LRL)

(UCLA) IGJP

$$h_1(1170)$$

$$I^G(J^{PC}) = 0^{+}(1^{-})$$

### $h_1(1170)$ MASS

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>1166 ± 5 ± 3</td><td>1 ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup> π<sup>0</sup> n</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

1168 ± 4 ANDO 92 SPEC

1190 ± 60 2 DANKOWY... 81 SPEC 0

<table><thead><tr><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>1 ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup> π<sup>0</sup> n</td></tr><tr><td>2 DANKOWY...</td><td>81</td><td>SPEC</td><td>8 π p → 3πn</td></tr></tbody></table>

¹Average and spread of values using 2 variants of the model of BOWLER 75.

²Uses the model of BOWLER 75.

### $h_1(1170)$ WIDTH

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>375 ± 6 ± 34</td><td>3 ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup> π<sup>0</sup> n</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

345 ± 6 ANDO 92 SPEC

320 ± 50 4 DANKOWY... 81 SPEC 0

<table><thead><tr><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>3 ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup> π<sup>0</sup> n</td></tr><tr><td>4 DANKOWY...</td><td>81</td><td>SPEC</td><td>8 π p → 3πn</td></tr></tbody></table>

³Average and spread of values using 2 variants of the model of BOWLER 75.

⁴Uses the model of BOWLER 75.

### $h_1(1170)$ DECAY MODES

<table><thead><tr><th>Mode</th><th>Fraction (Γ<sub>j</sub>/Γ)</th></tr></thead><tbody><tr><td>Γ<sub>1</sub> ρπ</td><td>seen</td></tr></tbody></table>

### $h_1(1170)$ BRANCHING RATIOS

<table><thead><tr><th>Γ(ρπ)/Γ<sub>total</sub></th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>• • • We do not use the following data for averages, fits, limits, etc. • • •</td><td></td><td></td><td></td><td></td></tr></tbody></table>

seen ANDO 92 SPEC

seen ATKINSON 84 SPEC

seen DANKOWY... 81 SPEC

### $h_1(1170)$ REFERENCES

ANDO 92 PL B291 496

ATKINSON 84 NP B231 15

DANKOWY... 81 PRL 46 580

BOWLER 75 NP B97 227

A. Ando et al. (KEK, KYOT, NIRS, SAGA+)

M. ATKINSON et al. (BONN, CERN, GLAS+)

J.A. Dankowych et al. (TNTO, BNL, CARL+)

M.G. Bowler et al. (OXFTP, DARE)

$$b_1(1235)$$

$$I^G(J^{PC}) = 1^{+}(1^{-})$$

### $b_1(1235)$ MASS

<table><thead><tr><th>VALUE (MeV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>1229.5 ± 3.2 OUR AVERAGE</td><td></td><td></td><td></td><td></td><td>See the ideogram below.</td></tr></tbody></table>

1225 ± 5 WEIDENAUER 93 ASTE

1235 ± 15 ALDE 92C GAM2

1236 ± 16 FUKUI 91 SPEC

1222 ± 6 ATKINSON 84E OMEG ±

1237 ± 7 ATKINSON 84E OMEG 0

1239 ± 5 EVANGELIS... 81 OMEG -

1251 ± 8 450 GESSAROLI 77 HBC -

1245 ± 11 890 FLATTE 76C HBC -

1222 ± 4 1400 CHALOUPKA 74 HBC -

1220 ± 7 600 KARSHON 74B HBC +

• • • We do not use the following data for averages, fits, limits, etc. • • •

1190 ± 10 AUGUSTIN 89 DM2 ±

1213 ± 5 ATKINSON 84C OMEG 0

1271 ± 11 COLLICK 84 SPEC +

### WEIGHTED AVERAGE
1229.5±3.2 (Error scaled by 1.6)

<figure><img src="image_449.png" /></figure>

### $b_1(1235)$ WIDTH

<table><thead><tr><th>VALUE (MeV)</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>142 ± 9 OUR AVERAGE</td><td></td><td></td><td></td><td></td><td>Error includes scale factor of 1.2.</td></tr><tr><td>113 ± 12 WEIDENAUER 93 ASTE</td><td></td><td></td><td></td><td></td><td>πp → 2π<sup>+</sup> 2π<sup>-</sup> π<sup>0</sup></td></tr><tr><td>160 ± 30 ALDE 92C GAM2</td><td></td><td></td><td></td><td></td><td>38,100 π<sup>-</sup> p → ωπ<sup>0</sup> n</td></tr><tr><td>151 ± 31 FUKUI 91 SPEC</td><td></td><td></td><td></td><td></td><td>8.95 π<sup>-</sup> p → ωπ<sup>0</sup> n</td></tr><tr><td>170 ± 15 EVANGELIS... 81 OMEG -</td><td></td><td></td><td></td><td></td><td>12 π<sup>-</sup> p → ωπ p</td></tr><tr><td>170 ± 50 225 BALTAY 78B HBC +</td><td></td><td></td><td></td><td></td><td>15 π<sup>+</sup> p → p4π</td></tr><tr><td>155 ± 32 450 GESSAROLI 77 HBC -</td><td></td><td></td><td></td><td></td><td>11 π<sup>-</sup> p → π<sup>-</sup> ωp</td></tr><tr><td>182 ± 45 FLATTE 76C HBC -</td><td></td><td></td><td></td><td></td><td>4.2 K<sup>-</sup> p → π<sup>-</sup> ωΣ<sup>+</sup></td></tr><tr><td>135 ± 20 1400 CHALOUPKA 74 HBC -</td><td></td><td></td><td></td><td></td><td>3.9 π<sup>-</sup> p</td></tr><tr><td>156 ± 22 600 KARSHON 74B HBC +</td><td></td><td></td><td></td><td></td><td>4.9 π<sup>+</sup> p</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

210 ± 19 AUGUSTIN 89 DM2 ±

231 ± 14 ATKINSON 84C OMEG 0

232 ± 29 COLLICK 84 SPEC +

### $b_1(1235)$ DECAY MODES

<table><thead><tr><th>Mode</th><th>Fraction (Γ<sub>j</sub>/Γ)</th><th>Confidence level</th></tr></thead><tbody><tr><td>Γ<sub>1</sub> ωπ</td><td>seen</td><td></td></tr><tr><td>[D/S amplitude ratio = 0.277 ± 0.027]</td><td></td><td></td></tr><tr><td>π<sup>±</sup>γ</td><td>(1.6 ± 0.4) × 10<sup>-3</sup></td><td></td></tr><tr><td>Γ<sub>3</sub> ηρ</td><td>seen</td><td></td></tr><tr><td>Γ<sub>4</sub> π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> π<sup>0</sup></td><td>&lt; 50 %</td><td>84%</td></tr><tr><td>Γ<sub>5</sub> K<sup>*</sup>(892) ± K<sup>∓</sup></td><td>seen</td><td></td></tr><tr><td>Γ<sub>6</sub> (K<sup>∓</sup>)<sup>±</sup> π<sup>0</sup></td><td>&lt; 8 %</td><td>90%</td></tr><tr><td>Γ<sub>7</sub> K<sup>0</sup><sub>S</sub> K<sup>0</sup><sub>L</sub> π<sup>±</sup></td><td>&lt; 6 %</td><td>90%</td></tr><tr><td>Γ<sub>8</sub> K<sup>0</sup><sub>S</sub> K<sup>0</sup><sub>L</sub> π<sup>±</sup></td><td>&lt; 2 %</td><td>90%</td></tr><tr><td>Γ<sub>9</sub> φπ</td><td>&lt; 1.5 %</td><td>84%</td></tr></tbody></table>

### $b_1(1235)$ PARTIAL WIDTHS

<table><thead><tr><th>Γ(π<sup>±</sup>γ)</th><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr><tr><td>230 ± 60</td><td></td><td>COLLICK</td><td>84 SPEC</td><td>+</td><td>200 π<sup>+</sup> Z → Zπω</td></tr></thead></table>

### $b_1(1235)$ D-wave/S-wave AMPLITUDE RATIO
IN DECAY OF $b_1(1235) → ωπ$

<table><thead><tr><th>VALUE</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>0.277 ± 0.027 OUR AVERAGE</td><td></td><td></td><td></td><td></td><td>Error includes scale factor of 2.4. See the ideogram below.</td></tr><tr><td>0.269 ± 0.009 ± 0.010</td><td></td><td>NOZAR 02 MPS</td><td>-</td><td></td><td>18 π<sup>-</sup> p → ωπ<sup>-</sup> p</td></tr><tr><td>0.23 ± 0.03</td><td></td><td>AMSLER 94C CBAR</td><td></td><td></td><td>0.0 πp → ωηπ<sup>0</sup></td></tr><tr><td>0.45 ± 0.04</td><td></td><td>AMSLER 93B CBAR</td><td></td><td></td><td>0.0 πp → ωπ<sup>0</sup> π<sup>0</sup></td></tr><tr><td>0.235 ± 0.047</td><td></td><td>ATKINSON 84C OMEG</td><td></td><td></td><td>20-70 γp</td></tr><tr><td>0.4 ± 0.1</td><td></td><td>GESSAROLI 77 HBC</td><td>-</td><td></td><td>11 π<sup>-</sup> p → π<sup>-</sup> ωp</td></tr><tr><td>-0.1</td><td></td><td>CHUNG 75B HBC</td><td>+</td><td></td><td>7.1 π<sup>+</sup> p</td></tr><tr><td>0.21 ± 0.08</td><td></td><td>CHALOUPKA 74 HBC</td><td>-</td><td></td><td>3.9-7.5 π<sup>-</sup> p</td></tr><tr><td>0.3 ± 0.1</td><td></td><td>KARSHON 74B HBC</td><td>+</td><td></td><td>4.9 π<sup>+</sup> p</td></tr><tr><td>0.35 ± 0.25</td><td>600</td><td></td><td></td><td></td><td></td></tr></tbody></table>
WEIGHTED AVERAGE
0.277±0.027 (Error scaled by 2.4)

<figure><img src="image_450.png" /><figcaption>b₁(1235) D-wave/S-wave amplitude ratio in decay of b₁(1235) → ωπ</figcaption></figure>

b₁(1235) D-wave/S-wave AMPLITUDE PHASE DIFFERENCE
IN DECAY OF b₁(1235) → ωπ

<table><thead><tr><th>VALUE (°)</th><th>DOCUMENT ID</th><th>TECN</th><th>CHG</th><th>COMMENT</th></tr></thead><tbody><tr><td>10.5±2.4±3.9</td><td>NOZAR</td><td>02</td><td>MPS</td><td>- 18 π<sup>-</sup> p → ωπ<sup>-</sup> p</td></tr></tbody></table>

b₁(1235) BRANCHING RATIOS

$$ \begin{array}{l} \Gamma(\eta\pi)/\Gamma(\omega\pi) \\ \text{VALUE} \\ <0.10 \end{array} $$

$$ \begin{array}{l} \Gamma(\pi^+\pi^+\pi^-\pi^0)/\Gamma(\omega\pi) \\ \text{VALUE} \\ <0.5 \end{array} $$

$$ \begin{array}{l} \Gamma(K^*(892)\pm K^\mp)/\Gamma_{\text{total}} \\ \text{VALUE} \\ \text{seen} \end{array} $$

¹ From a fit including ten additional resonances and energy-independent Breit-Wigner width.

$$ \begin{array}{l} \Gamma((K\bar{K})^\pm\pi^0)/\Gamma(\omega\pi) \\ \text{VALUE} \\ <0.08 \end{array} $$

$$ \begin{array}{l} \Gamma(K_S^0 K_L^0 \pi^\pm)/\Gamma(\omega\pi) \\ \text{VALUE} \\ <0.06 \end{array} $$

$$ \begin{array}{l} \Gamma(K_S^0 K_S^0 \pi^\pm)/\Gamma(\omega\pi) \\ \text{VALUE} \\ <0.02 \end{array} $$

$$ \begin{array}{l} \Gamma(\phi\pi)/\Gamma(\omega\pi) \\ \text{VALUE} \\ <0.004 \end{array} $$

• • • We do not use the following data for averages, fits, limits, etc. • • •

<0.04 95 BIZZARRI 69 HBC ± 0.0 $\bar{p}p$
<0.015 DAHL 67 HBC 1.6–4.2 $\pi^-$ p

b₁(1235) REFERENCES

<table><tbody><tr><td>ABLIKIM</td><td>10E</td><td>PL B693 88</td><td>M. Ablikim et al.</td><td>(BES II Collab.)</td></tr><tr><td>NOZAR</td><td>02</td><td>PL B541 35</td><td>M. Nozar et al.</td><td></td></tr><tr><td>VIKTOROV</td><td>96</td><td>PAN 59 1184</td><td>V.A. Viktorov et al.</td><td>(SERP)</td></tr><tr><td>AMSLER</td><td>94C</td><td>PL B327 425</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>AMSLER</td><td>93B</td><td>PL B311 362</td><td>C. Amsler et al.</td><td>(Crystal Barrel Collab.)</td></tr><tr><td>WEIDENAUER</td><td>93</td><td>ZPHY C59 387</td><td>P. Weidenauer et al.</td><td>(ASTERIX Collab.)</td></tr><tr><td>ALDE</td><td>92C</td><td>ZPHY C54 553</td><td>D.M. Alde et al.</td><td>(BELG, SERP, KEK, LANL+)</td></tr><tr><td>FUKUI</td><td>91</td><td>PL B257 241</td><td>S. Fukui et al.</td><td>(SUGI, NAGO, KEK, KYOT+)</td></tr><tr><td>AUGUSTIN</td><td>89</td><td>NP B320 1</td><td>J.E. Augustin, G. Cosme</td><td>(DM2 Collab.)</td></tr><tr><td>ATKINSON</td><td>84C</td><td>NP B243 1</td><td>M. Atkinson et al.</td><td>(BONN, CERN, GLAS+,) JP</td></tr><tr><td>ATKINSON</td><td>84D</td><td>NP B242 269</td><td>M. Atkinson et al.</td><td>(BONN, CERN, GLAS+)</td></tr><tr><td>ATKINSON</td><td>84E</td><td>PL B138 459</td><td>M. Atkinson et al.</td><td>(BONN, CERN, GLAS+)</td></tr><tr><td>COLLICK</td><td>84</td><td>PRL 53 2374</td><td>B. Collick et al.</td><td>(MINN, ROCH, FNAL)</td></tr><tr><td>EVANGELIS...</td><td>81</td><td>NP B187 197</td><td>C. Evangelista et al.</td><td>(BARI, BONN, CERN+)</td></tr><tr><td>BALTAY</td><td>78B</td><td>PR D17 62</td><td>C. Baltay et al.</td><td>(COLU, BING)</td></tr><tr><td>GESSAROLI</td><td>77</td><td>NP B126 382</td><td>R. Gessaroli et al.</td><td>(BGNA, FIRZ, GENO+,) JP</td></tr><tr><td>FLATTE</td><td>76C</td><td>PL 64B 225</td><td>S.M. Flatte et al.</td><td>(CERN, AMST, NIUM+,) JP</td></tr><tr><td>CHUNG</td><td>75B</td><td>PR D11 2426</td><td>S.U. Chung et al.</td><td>(BNL, LBL, UCSC) JP</td></tr><tr><td>CHALOUPKA</td><td>74</td><td>PL 51B 407</td><td>V. Chaloupka et al.</td><td>(CERN) JP</td></tr><tr><td>KARSHON</td><td>74B</td><td>PR D10 3608</td><td>U. Karshon et al.</td><td>(REHO) JP</td></tr><tr><td>BIZZARRI</td><td>69</td><td>NP B14 169</td><td>R. Bizzarri et al.</td><td>(CERN, CDEF)</td></tr><tr><td>BALTAY</td><td>67</td><td>PRL 18 93</td><td>C. Baltay et al.</td><td>(COLU)</td></tr><tr><td>DAHL</td><td>67</td><td>PR 163 1377</td><td>O.I. Dahl et al.</td><td>(LRL)</td></tr><tr><td>ABOLINS</td><td>63</td><td>PRL 11 381</td><td>M.A. Abolins et al.</td><td>(UCSD)</td></tr></tbody></table>

$$ a_1(1260) $$

$$ I^G(J^PC) = 1^{-}(1^{++}) $$

See also our review under the a₁(1260) in PDG 06, Journal of Physics G33 1 (2006).

a₁(1260) T-MATRIX POLE $\sqrt{s}$

Note that $\Gamma = -2 \operatorname{Im}(\sqrt{s})$.

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>(1209<sup>+13</sup><sub>-10</sub>)<sup>-i</sup>(288<sup>+45</sup><sub>-12</sub>)</td><td colspan="3">OUR ESTIMATE</td></tr><tr><td>(1209<sup>+4</sup><sub>-9</sub>)<sup>+12</sup><sup>-i</sup>(288<sup>+6</sup><sub>-10</sub>)</td><td>MIKHASENKO</td><td>18B</td><td>RVUE</td><td>$\tau^{-} \rightarrow \pi^{-}\pi^{+}\pi^{-}\nu_{\tau}$</td></tr></tbody></table>

a₁(1260) MASS

<table><thead><tr><th>VALUE (MeV)</th><th>±40</th><th>OUR ESTIMATE</th><th>EVTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>1230</td><td>±12</td><td></td><td></td><td>1 AGHASYAN</td><td>18B</td><td>COMP</td><td>190 π<sup>-</sup> p → π<sup>-</sup> π<sup>+</sup> π<sup>-</sup> p</td></tr><tr><td>1299</td><td>±28</td><td></td><td></td><td>46M</td><td></td><td></td><td></td></tr><tr><td colspan="8">• • • We do not use the following data for averages, fits, limits, etc. • • •</td></tr><tr><td>1195.05</td><td>± 1.05</td><td>6.33</td><td>894k</td><td>AAIJ</td><td>18AI</td><td>LHCB</td><td>D<sup>0</sup> → K<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup></td></tr><tr><td>1225</td><td>± 9</td><td>±20</td><td>7k</td><td>2 DARGENT</td><td>17</td><td>RVUE</td><td>D<sup>0</sup> → π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup></td></tr><tr><td>1255</td><td>± 6</td><td>±7</td><td>420k</td><td>3 ALEKSEEV</td><td>10</td><td>COMP</td><td>190 π<sup>-</sup> P<sup>b</sup> → π<sup>-</sup> π<sup>+</sup> π<sup>-</sup> P<sup>b</sup></td></tr><tr><td>1243</td><td>±12</td><td>±20</td><td></td><td>4 AUBERT</td><td>07AU</td><td>BABR</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> π<sup>+</sup> π<sup>-</sup></td></tr><tr><td>1230-1270</td><td></td><td></td><td>6360</td><td>5 LINK</td><td>07A</td><td>FOCS</td><td>D<sup>0</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> π<sup>+</sup></td></tr><tr><td>1203</td><td>± 3</td><td></td><td></td><td>6 GOMEZ-DUM.<sup>04</sup></td><td>04</td><td>RVUE</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> π<sup>+</sup></td></tr><tr><td>1330</td><td>±24</td><td></td><td>90k</td><td>SALVINI</td><td>04</td><td>OBLX</td><td>π<sup>+</sup> p → 2π<sup>+</sup>2π<sup>-</sup></td></tr><tr><td>1331</td><td>±10</td><td>± 3</td><td>37k</td><td>7 ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → τ<sup>+</sup> τ<sup>-</sup>, τ<sup>-</sup> → π<sup>-</sup> π<sup>0</sup> π<sup>0</sup> ν<sub>τ</sub></td></tr><tr><td colspan="8">• • • We do not use the following data for averages, fits, limits, etc. • • •</td></tr><tr><td>1255</td><td>± 7</td><td>± 6</td><td>5904</td><td>8 ABREU</td><td>98B</td><td>DLPH</td><td>e<sup>+</sup> e<sup>-</sup></td></tr><tr><td>1207</td><td>± 5</td><td>± 8</td><td>5904</td><td>9 ABREU</td><td>98B</td><td>DLPH</td><td>e<sup>+</sup> e<sup>-</sup></td></tr><tr><td>1196</td><td>± 4</td><td>± 5</td><td>5904</td><td>10,11 ABREU</td><td>98B</td><td>DLPH</td><td>e<sup>+</sup> e<sup>-</sup></td></tr><tr><td>1240</td><td>±10</td><td></td><td></td><td>BARBERIS</td><td>98B</td><td></td><td>450 p p → p<sub>f</sub> π<sup>+</sup> π<sup>-</sup> π<sup>0</sup> p<sub>S</sub></td></tr><tr><td>1262</td><td>± 9</td><td>± 7</td><td></td><td>8,12 ACKERSTAFF</td><td>97R</td><td>OPAL</td><td>E<sup>ee</sup><sub>cm</sub>= 88-94, τ → 3πν</td></tr><tr><td>1210</td><td>± 7</td><td>± 2</td><td></td><td>9,12 ACKERSTAFF</td><td>97R</td><td>OPAL</td><td>E<sup>ee</sup><sub>cm</sub>= 88-94, τ → 3πν</td></tr><tr><td>1211</td><td>± 7</td><td>±50</td><td>-0</td><td>9 ALBRECHT</td><td>93C</td><td>ARG</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1121</td><td>± 8</td><td></td><td></td><td>13 ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup> π<sup>-</sup> π<sup>0</sup> n</td></tr><tr><td>1242</td><td>±37</td><td></td><td></td><td>14 IVANOV</td><td>91</td><td>RVUE</td><td>τ → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1260</td><td>±14</td><td></td><td></td><td>15 IVANOV</td><td>91</td><td>RVUE</td><td>τ → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1250</td><td>± 9</td><td></td><td></td><td>16 IVANOV</td><td>91</td><td>RVUE</td><td>τ → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1208</td><td>±15</td><td></td><td></td><td>ARMSTRONG</td><td>90</td><td>OMEG</td><td>300.0 p p → p p π<sup>+</sup> π<sup>-</sup> π<sup>0</sup></td></tr><tr><td>1220</td><td>±15</td><td></td><td></td><td>17 ISGUR</td><td>89</td><td>RVUE</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1260</td><td>±25</td><td></td><td></td><td>18 BOWLER</td><td>88</td><td>RVUE</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1166</td><td>±18</td><td>±11</td><td></td><td>BAND</td><td>87</td><td>MAC</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1164</td><td>±41</td><td>±23</td><td></td><td>BAND</td><td>87</td><td>MAC</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>0</sup> π<sup>0</sup> ν</td></tr><tr><td>1250</td><td>±40</td><td></td><td></td><td>17 TORNQVIST</td><td>87</td><td>RVUE</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1046</td><td>±11</td><td></td><td></td><td>ALBRECHT</td><td>86B</td><td>ARG</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1056</td><td>±20</td><td>±15</td><td></td><td>RUCKSTUHL</td><td>86</td><td>DLCO</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1194</td><td>±14</td><td>±10</td><td></td><td>SCHMIDKE</td><td>86</td><td>MRK2</td><td>τ<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> ν</td></tr><tr><td>1255</td><td>±23</td><td></td><td></td><td>BELLINI</td><td>85</td><td>SPEC</td><td>40 π<sup>-</sup> A<sup>+</sup> → π<sup>+</sup> π<sup>+</sup> π<sup>-</sup> A</td></tr><tr><td>1240</td><td>±80</td><td></td><td></td><td>19 DANKOWY...</td><td>81</td><td>SPEC</td><td>8.45 π<sup>-</sup> p → n3π</td></tr><tr><td>1280</td><td>±30</td><td></td><td></td><td>19 DAUM</td><td>81B</td><td>CNTR</td><td>63.94 π<sup>-</sup> p → p3π</td></tr><tr><td>1041</td><td>±13</td><td></td><td></td><td>20 GAVILLET</td><td>77</td><td>HBC</td><td>4.2 K<sup>-</sup> p → Σ3π</td></tr></tbody></table>

¹ Statistical error negligible.

² Reanalysis of CLEO data using Breit-Wigner parameterization.

³ Superseded by AGHASYAN 2018B.

⁴ The $p\bar{p}\pi^\mp$ state can be also due to the $\pi(1300)$.

⁵ Using the Breit-Wigner parameterization; strong correlation between mass and width.

⁶ Using the data of BARATE 98R.

⁷ From a fit to the $3\pi$ mass spectrum including the $K\bar{K}^*$ (892) threshold.

⁸ Uses the model of KUHN 90.

⁹ Uses the model of ISGUR 89.

¹⁰ Includes the effect of a possible $a'_1$ state.

¹¹ Uses the model of FEINDT 90.

¹² Supersedes AKERS 95p.

¹³ Average and spread of values using 2 variants of the model of BOWLER 75.

¹⁴ Reanalysis of RUCKSTUHL 86.

¹⁵ Reanalysis of SCHMIDKE 86.

¹⁶ Reanalysis of ALBRECHT 86b.

¹⁷ From a combined reanalysis of ALBRECHT 86b, SCHMIDKE 86, and RUCKSTUHL 86.

¹⁸ From a combined reanalysis of ALBRECHT 86b and DAUM 81b.

¹⁹ Uses the model of BOWLER 75.

²⁰ Produced in $K^-$ backward scattering.

a₁(1260) WIDTH

<table><thead><tr><th>VALUE (MeV)</th><th>±80</th><th>EVENTS</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>250</td><td>to 600</td><td>OUR ESTIMATE</td><td>1 AGHASYAN</td><td>18B</td><td>COMP</td><td>190 π<sup>-</sup> p → π<sup>-</sup> π<sup>+</sup> π<sup>-</sup> p</td></tr><tr><td>380</td><td></td><td>46M</td><td></td><td></td><td></td><td></td></tr></tbody></table>
# Meson Particle Listings

## a₁(1260)

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>422.01 ± 2.10 ± 12.72</td><td>894k</td><td>AAIJ</td><td>18AI</td><td>LHCB</td><td>D<sup>0</sup> → K<sup>±</sup>π<sup>±</sup>π<sup>±</sup>π<sup>±</sup></td></tr><tr><td>430 ± 24 ± 31</td><td></td><td>2 DARGENT</td><td>17</td><td>RVUE</td><td>D<sup>0</sup> → π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>+</sup></td></tr><tr><td>367 ± 9 ± 28</td><td>420k</td><td>3 ALEKSEEV</td><td>10</td><td>COMP</td><td>190 π<sup>-</sup> Pb<sup>-</sup> → π<sup>-</sup>π<sup>+</sup> π<sup>+</sup> Pb<sup>+</sup></td></tr><tr><td>410 ± 31 ± 30</td><td></td><td>4 AUBERT</td><td>07AU</td><td>BABR</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>-</sup> → π<sup>-</sup>π<sup>0</sup>π<sup>0</sup>ν<sub>τ</sub></td></tr><tr><td>520-680</td><td></td><td>5 LINK</td><td>07A</td><td>FOCS</td><td>D<sup>0</sup> → π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup>π<sup>+</sup></td></tr><tr><td>480 ± 20</td><td>6360</td><td>6 GOMEZ-DUM...</td><td>04</td><td>RVUE</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν<sub>τ</sub></td></tr><tr><td>580 ± 41</td><td></td><td>SALVINI</td><td>04</td><td>OBLX</td><td>ρp → 2π<sup>+</sup>2π<sup>-</sup></td></tr><tr><td>460 ± 85</td><td></td><td>7 DRUTSKOY</td><td>02</td><td>BELL</td><td>B → D<sup>(*)</sup> K<sup>-</sup> K<sup>+</sup>0</td></tr><tr><td>814 ± 36 ± 13</td><td>37k</td><td>8 ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>-</sup> → π<sup>-</sup>π<sup>0</sup>π<sup>0</sup>ν<sub>τ</sub></td></tr><tr><td>450 ± 50</td><td>22k</td><td>9 AKHMETSHIN 99E</td><td>CMD2</td><td></td><td>1.05-1.38 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>π<sup>0</sup></td></tr><tr><td>570 ± 10</td><td></td><td>10 BONDAR</td><td>99</td><td>RVUE</td><td>e<sup>+</sup> e<sup>-</sup> → 4π, τ → 3πν</td></tr><tr><td>587 ± 27 ± 21</td><td>5904</td><td>11 ABREU</td><td>98G</td><td>DLPH</td><td>e<sup>+</sup> e<sup>-</sup></td></tr><tr><td>478 ± 3 ± 15</td><td>5904</td><td>12 ABREU</td><td>98G</td><td>DLPH</td><td>e<sup>+</sup> e<sup>-</sup></td></tr><tr><td>425 ± 14 ± 8</td><td>5904</td><td>13,14 ABREU</td><td>98G</td><td>DLPH</td><td>e<sup>+</sup> e<sup>-</sup></td></tr><tr><td>400 ± 35</td><td></td><td>BARBERIS</td><td>98B</td><td></td><td>450 pp →</td></tr><tr><td>621 ± 32 ± 58</td><td></td><td>11,15 ACKERSTAFF</td><td>97R</td><td>OPAL</td><td>ρf π<sup>+</sup> π<sup>-</sup> π<sup>0</sup> ρ<sub>S</sub> → e<sup>+</sup> e<sup>-</sup> → 3πν</td></tr><tr><td>457 ± 15 ± 17</td><td></td><td>12,15 ACKERSTAFF</td><td>97R</td><td>OPAL</td><td>ρf π<sup>+</sup> π<sup>-</sup> π<sup>0</sup> ρ<sub>S</sub> → e<sup>+</sup> e<sup>-</sup> → 3πν</td></tr><tr><td>446 ± 21 ± 140</td><td>0</td><td>12 ALBRECHT</td><td>93C</td><td>ARG</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>239 ± 11</td><td></td><td>ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>n</td></tr><tr><td>266 ± 13 ± 4</td><td></td><td>16 ANDO</td><td>92</td><td>SPEC</td><td>8 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup>π<sup>0</sup>n</td></tr><tr><td>465 ± 228</td><td>-143</td><td>17 IVANOV</td><td>91</td><td>RVUE</td><td>τ → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>298 ± 40 ± 34</td><td></td><td>18 IVANOV</td><td>91</td><td>RVUE</td><td>τ → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>488 ± 32</td><td></td><td>19 IVANOV</td><td>91</td><td>RVUE</td><td>τ → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>430 ± 50</td><td></td><td>ARMSTRONG</td><td>90</td><td>OMEG</td><td>300.0 pp → ρpπ<sup>+</sup> π<sup>-</sup> π<sup>0</sup></td></tr><tr><td>420 ± 40</td><td></td><td>20 ISGUR</td><td>89</td><td>RVUE</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>396 ± 43</td><td></td><td>21 BOWLER</td><td>88</td><td>RVUE</td><td></td></tr><tr><td>405 ± 75 ± 25</td><td></td><td>BAND</td><td>87</td><td>MAC</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>419 ± 108 ± 57</td><td></td><td>BAND</td><td>87</td><td>MAC</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>0</sup>π<sup>0</sup>ν</td></tr><tr><td>521 ± 27</td><td></td><td>ALBRECHT</td><td>86B</td><td>ARG</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>476 ± 132</td><td>± 54</td><td>RUCKSTUHL</td><td>86</td><td>DLCO</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>462 ± 56 ± 30</td><td></td><td>SCHMIDKE</td><td>86</td><td>MRK2</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr><tr><td>292 ± 40</td><td></td><td>BELLINI</td><td>85</td><td>SPEC</td><td>40 π<sup>-</sup> A → π<sup>-</sup>π<sup>+</sup>π<sup>-</sup> A</td></tr><tr><td>380 ± 100</td><td></td><td>22 DANKOWY...</td><td>81</td><td>SPEC</td><td>8.45 π<sup>-</sup> p → n3π</td></tr><tr><td>300 ± 50</td><td></td><td>22 DAUM</td><td>81B</td><td>CNTR</td><td>63.94 π<sup>-</sup> p → ρ3π</td></tr><tr><td>230 ± 50</td><td></td><td>23 GAVILLET</td><td>77</td><td>HBC</td><td>4.2 K<sup>-</sup> p → Σ3π</td></tr></tbody></table>

1 Statistical error negligible.

2 Reanalysis of CLEO data using Breit-Wigner parameterization.

3 Supersedes by AGHASYAN 2018B.

4 The $\rho^{\pm}\pi^{\mp}$ state can be also due to the $\pi(1300)$.

5 Using the Breit-Wigner parameterization; strong correlation between mass and width.

6 Using the data of BARATE 89R.

7 From a fit of the $K^{-}K^{+0}$ distribution assuming $m_{a_1} = 1230$ MeV and purely resonant production of the $K^{-}K^{+0}$ system.

8 From a fit to the $3\pi$ mass spectrum including the $K^{\bar{R}}(892)$ threshold.

9 Using the $a_1(1260)$ mass of 1230 MeV.

10 From AKHMETSHIN 99E and ASNER 00 data using the $a_1(1260)$ mass of 1230 MeV.

11 Uses the model of KUHN 90.

12 Uses the model of ISGUR 89.

13 Includes the effect of a possible $a'_1$ state.

14 Uses the model of FEINDT 90.

15 Supersedes AKERS 95P.

16 Average and spread of values using 2 variants of the model of BOWLER 75.

17 Reanalysis of RUCKSTUHL 86.

18 Reanalysis of SCHMIDKE 86.

19 Reanalysis of ALBRECHT 86B.

20 From a combined reanalysis of ALBRECHT 86b, SCHMIDKE 86, and RUCKSTUHL 86.

21 From a combined reanalysis of ALBRECHT 86b and DAUM 81B.

22 Uses the model of BOWLER 75.

23 Produced in $K^{-}$ backward scattering.

## a₁(1260) DECAY MODES

<table><thead><tr><th>Mode</th><th>Fraction (Γ<sub>i</sub>/Γ)</th></tr></thead><tbody><tr><td>Γ<sub>1</sub> 3π</td><td>seen</td></tr><tr><td>Γ<sub>2</sub> (ρπ)<sub>S-wave</sub>, ρ → ππ</td><td>seen</td></tr><tr><td>Γ<sub>3</sub> (ρπ)<sub>D-wave</sub>, ρ → ππ</td><td>seen</td></tr><tr><td>Γ<sub>4</sub> (ρ(1450)π)<sub>S-wave</sub>, ρ → ππ</td><td>seen</td></tr><tr><td>Γ<sub>5</sub> (ρ(1450)π)<sub>D-wave</sub>, ρ → ππ</td><td>seen</td></tr><tr><td>Γ<sub>6</sub> f<sub>0</sub>(500)π, f<sub>0</sub> → ππ</td><td>seen</td></tr></tbody></table>

<table><tbody><tr><td>Γ<sub>7</sub></td><td>f<sub>0</sub>(980)π, f<sub>0</sub> → ππ</td><td>seen</td></tr><tr><td>Γ<sub>8</sub></td><td>f<sub>0</sub>(1370)π, f<sub>0</sub> → ππ</td><td>seen</td></tr><tr><td>Γ<sub>9</sub></td><td>f<sub>2</sub>(1270)π, f<sub>2</sub> → ππ</td><td>seen</td></tr><tr><td>Γ<sub>10</sub></td><td>π<sup>+</sup>π<sup>-</sup>π<sup>0</sup></td><td>seen</td></tr><tr><td>Γ<sub>11</sub></td><td>π<sup>0</sup>π<sup>0</sup>π<sup>0</sup></td><td>not seen</td></tr><tr><td>Γ<sub>12</sub></td><td>KKπ</td><td>seen</td></tr><tr><td>Γ<sub>13</sub></td><td>K<sup>*</sup>(892)K</td><td>seen</td></tr><tr><td>Γ<sub>14</sub></td><td>πγ</td><td>seen</td></tr></tbody></table>

## a₁(1260) PARTIAL WIDTHS

<table><thead><tr><th>Γ(πγ)</th><th>VALUE (keV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td></td><td>640 ± 246</td><td>ZIELINSKI</td><td>84C</td><td>200 π<sup>+</sup> Z → Z3π</td></tr></tbody></table>

## D-wave/S-wave AMPLITUDE RATIO IN DECAY OF a₁(1260) → ρπ

<table><thead><tr><th>VALUE</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>-0.062 ± 0.020</td><td>OUR AVERAGE</td><td>Error includes scale</td><td>factor of 2.3. See the ideogram below.</td></tr><tr><td>-0.043 ± 0.009 ± 0.005</td><td></td><td>LINK</td><td>07A FOCS</td><td>D<sup>0</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup></td></tr><tr><td>-0.14 ± 0.04 ± 0.07</td><td></td><td>1 CHUNG</td><td>02 B852</td><td>18.3 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup>π<sup>-</sup>π<sup>+</sup>π<sup>-</sup>π<sup>+</sup></td></tr><tr><td>-0.10 ± 0.02 ± 0.02</td><td></td><td>2.3 ACKERSTAFF</td><td>97R OPAL</td><td>E<sup>ee</sup><sub>cm</sub>= 88-94, τ → 3πν</td></tr><tr><td>-0.11 ± 0.02</td><td></td><td>2 ALBRECHT</td><td>93C ARG</td><td>τ<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>π<sup>-</sup>ν</td></tr></tbody></table>

1 Deck-type background not subtracted.

2 Uses the model of ISGUR 89.

3 Supersedes AKERS 95P.

<figure><img src="image_451.png" /><figcaption>D-wave/S-wave AMPLITUDE RATIO IN DECAY OF a₁(1260) → ρπ</figcaption></figure>

## a₁(1260) BRANCHING RATIOS

<table><thead><tr><th>Γ(ρπ)<sub>S-wave</sub>, ρ → ππ)</th><th>Γ<sub>2</sub>/Γ</th></tr></thead><tbody><tr><td>60.19</td><td>37k 1 ASNER 00 CLE2</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>1.30 ± 0.60 ± 0.22</td><td>37k 1 ASNER 00 CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → τ<sup>+</sup>τ<sup>-</sup>,<br>τ<sup>-</sup> → π<sup>-</sup>π<sup>0</sup>π<sup>0</sup>ν<sub>τ</sub></td></tr></tbody></table>

1 From a fit to the Dalitz plot.

<table><thead><tr><th>Γ(ρπ)<sub>D-wave</sub>, ρ → ππ)</th><th>Γ<sub>3</sub>/Γ</th></tr></thead><tbody><tr><td>60.19</td><td>37k 1 ASNER 00 CLE2</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>0.56 ± 0.84 ± 0.32</td><td>37k 1,2 ASNER 00 CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → τ<sup>+</sup>τ<sup>-</sup>,<br>τ<sup>-</sup> → π<sup>-</sup>π<sup>0</sup>π<sup>0</sup>ν<sub>τ</sub></td></tr></tbody></table>

1 From a fit to the Dalitz plot.

<table><thead><tr><th>Γ(ρ(1450)π)<sub>S-wave</sub>, ρ → ππ)</th><th>Γ<sub>4</sub>/Γ</th></tr></thead><tbody><tr><td>60.19</td><td>37k 1,2 ASNER 00 CLE2</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>0.56 ± 0.84 ± 0.32</td><td>37k 1,2 ASNER 00 CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → τ<sup>+</sup>τ<sup>-</sup>,<br>τ<sup>-</sup> → π<sup>-</sup>π<sup>0</sup>π<sup>0</sup>ν<sub>τ</sub></td></tr></tbody></table>

1 From a fit to the Dalitz plot.

2 Assuming for ρ(1450) mass and width of 1370 and 386 MeV respectively.

<table><thead><tr><th>Γ(ρ(1450)π)<sub>D-wave</sub>, ρ → ππ)</th><th>Γ<sub>5</sub>/Γ</th></tr></thead><tbody><tr><td>60.19</td><td>37k 1,2 ASNER 00 CLE2</td></tr></tbody></table>

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tbody><tr><td>2.04 ± 1.20 ± 0.28</td><td>37k 1,2 ASNER 00 CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → τ<sup>+</sup>τ<sup>-</sup>,<br>τ<sup>-</sup> → π<sup>-</sup>π<sup>0</sup>π<sup>0</sup>ν<sub>τ</sub></td></tr></tbody></table>

1 From a fit to the Dalitz plot.

2 Assuming for ρ(1450) mass and width of 1370 and 386 MeV respectively.
Γ(f₀(500)π, f₀ → ππ)/Γ_{total} Γ_{6/Γ}

VALUE (units 10⁻²) EVTS DOCUMENT ID TECN COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>seen</td><td>CHUNG</td><td>02</td><td>B582</td><td>18.3 π<sup>-</sup> p → π<sup>+</sup>π<sup>-</sup> π<sup>-</sup> p</td></tr><tr><td>18.76 ± 4.29 ± 1.48</td><td>37k</td><td>1,2 ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>, π<sup>-</sup> → π<sup>-</sup> π<sub>0</sub> π<sub>0</sub> ν<sub>τ</sub></td></tr></table>

¹From a fit to the Dalitz plot.

²Assuming for f₀(500) (σ) mass and width of 860 and 880 MeV respectively.

Γ(f₀(500)π, f₀ → ππ)/[Γ((ρπ)S-wave, ρ → ππ) + Γ((ρπ)S-wave, ρ → ππ)] Γ_{6/(Γ₂+Γ₂)}

VALUE EVTS DOCUMENT ID TECN COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>0.06 ± 0.05</td><td>90k</td><td>SALVINI</td><td>04</td><td>OBLX</td><td>p̄p → 2π<sup>+</sup>2π<sup>-</sup></td></tr><tr><td>~ 0.3</td><td>28k</td><td>AKHMETSHIN</td><td>99e</td><td>CMD2</td><td>1.05–1.38 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup> π<sup>+</sup> π<sup>-</sup></td></tr><tr><td>0.003 ± 0.003</td><td></td><td>1 LONGACRE</td><td>82</td><td>RVUE</td><td></td></tr></table>

¹Uses multichannel Aitchison-Bowler model (BOWLER 75). Uses data from GAVIL-LET 77, DAUM 80, and DANKOWYCH 81.

Γ(f₀(980)π, f₀ → ππ)/Γ_{total} Γ_{7/Γ}

VALUE EVTS DOCUMENT ID TECN COMMENT

seen 1 ALEXEEV 21 COMP π⁻p → π⁻π⁺π⁺p

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>not seen</td><td>37k</td><td>ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>, π<sup>-</sup> → π<sup>-</sup> π<sub>0</sub> π<sub>0</sub> ν<sub>τ</sub></td></tr></table>

¹The a₁(1260)⁻ → f₀(980)π⁻ decay mode via the Triangle Singularity mechanism from MIKHASENKO 15 and ACETI 16 explains the a₁(1420)⁻ signal observed by ADOLPH 15c.

Γ(f₀(1370)π, f₀ → ππ)/Γ_{total} Γ_{8/Γ}

VALUE (units 10⁻²) EVTS DOCUMENT ID TECN COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>7.40 ± 2.71 ± 1.26</td><td>37k</td><td>1,2 ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>, π<sup>-</sup> → π<sup>-</sup> π<sub>0</sub> π<sub>0</sub> ν<sub>τ</sub></td></tr></table>

¹From a fit to the Dalitz plot.

²Assuming for f₀(1370) mass and width of 1186 and 350 MeV respectively.

Γ(f₂(1270)π, f₂ → ππ)/Γ_{total} Γ_{9/Γ}

VALUE (units 10⁻²) EVTS DOCUMENT ID TECN COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>1.19 ± 0.49 ± 0.17</td><td>37k</td><td>1,2 ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → π<sup>+</sup>π<sup>-</sup>, π<sup>-</sup> → π<sup>-</sup> π<sub>0</sub> π<sub>0</sub> ν<sub>τ</sub></td></tr></table>

¹From a fit to the Dalitz plot.

²Assuming for f₂(1270) mass and width of 1275 and 185 MeV respectively.

Γ(π⁺π⁻π⁰)/Γ_{total} Γ_{10/Γ}

VALUE EVTS DOCUMENT ID TECN COMMENT

seen BARBERIS 98B 450 pp → p_f π⁺π⁻π⁰ p_s

Γ(π⁰π⁰π⁰)/Γ(π⁺π⁻π⁰) Γ_{11/Γ10}

VALUE CL% DOCUMENT ID TECN COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>&lt;0.008</td><td>90</td><td>1 BARBERIS</td><td>01</td><td>450 pp → p_f 3π⁰ p_s</td></tr></table>

¹Inconsistent with observations of σπ, f₀(1370)π, and f₂(1270)π decay modes.

Γ(K*(892)K)/Γ_{total} Γ_{13/Γ}

VALUE (units 10⁻²) EVTS DOCUMENT ID TECN COMMENT

• • • We do not use the following data for averages, fits, limits, etc. • • •

<table><tr><td>2.2 ± 0.5</td><td>2255</td><td>1 COAN</td><td>04</td><td>CLEO</td><td>τ⁻ → K⁻π⁻K⁺ν<sub>τ</sub></td></tr><tr><td>8 to 15</td><td>205</td><td>2 DRUTSKOY</td><td>02</td><td>BELL</td><td>B → D(+) K⁻K⁺π<sup>0</sup> T</td></tr><tr><td>3.3 ± 0.5 ± 0.1</td><td>37k</td><td>3 ASNER</td><td>00</td><td>CLE2</td><td>10.6 e<sup>+</sup> e<sup>-</sup> → τ<sup>+</sup>π<sup>-</sup>, π<sup>-</sup> → π<sup>-</sup> π<sub>0</sub> π<sub>0</sub> ν<sub>τ</sub></td></tr><tr><td>2.6 ± 0.3</td><td></td><td>4 BARATE</td><td>99r</td><td>ALEC</td><td>τ → K<sup>-</sup>π<sup>-</sup>ν<sub>τ</sub></td></tr></table>

¹Using structure functions from KUHN 92 and DECKER 93A and B(τ⁻ → K⁻π⁻K⁺ν<sub>τ</sub>) = (0.155 ± 0.006 ± 0.009)% from BRIERE 03.

²From a comparison to ALAM 94 assuming purely resonant production of the K⁻K⁺* system.

³From a fit to the 3π mass spectrum including the K⁻K⁺* (892) threshold.

⁴Assuming a₁(1260) dominance and taking B(τ⁻ → a₁(1260)ντ) from BUSKULIC 96.

a₁(1260) REFERENCES

<table><tr><td>ALEXEEV</td><td>21</td><td>PRL 127 082501</td><td>G.D. Alexeev et al.</td><td>(COMPASS Collab.)</td></tr><tr><td>AAIJ</td><td>18AI</td><td>EPJ C78 443</td><td>R. Aaij et al.</td><td>(LHCb Collab.)</td></tr><tr><td>AGHASYAN</td><td>18B</td><td>PR D98 092003</td><td>M. Aghasyan et al.</td><td>(COMPASS Collab.)</td></tr><tr><td>MIKHASENKO</td><td>18</td><td>PR D98 096021</td><td>M. Mikhasenko et al.</td><td>(JPAC Collab.)</td></tr><tr><td>DARGENT</td><td>17</td><td>JHEP 1705 143</td><td>P. dArgent et al.</td><td>(HEID, BRIS)</td></tr><tr><td>ACETI</td><td>16</td><td>PR D94 096015</td><td>F. Aceti, L.R. Dai, E. Oset</td><td>(IFIC, LNUDA)</td></tr><tr><td>ADOLPH</td><td>15C</td><td>PRL 115 082001</td><td>C. Adolph et al.</td><td>(COMPASS Collab.)</td></tr><tr><td>MIKHASENKO</td><td>15</td><td>PR D91 094015</td><td>M. Mikhasenko, B. Ketter, A. Sarantsev</td><td>(BONN+)</td></tr><tr><td>ALEKSEEV</td><td>10</td><td>PRL 104 241803</td><td>M.G. Alekseev et al.</td><td>(COMPASS Collab.)</td></tr><tr><td>AUBERT</td><td>07AU</td><td>PR D76 092005</td><td>B. Aubert et al.</td><td>(BABAR Collab.)</td></tr></table>

<table><tr><td>LINK</td><td>07A</td><td>PR D75 052003</td><td>J.M. Link et al.</td><td>(FNAL FOCUS Collab.)</td></tr><tr><td>PDG</td><td>06</td><td>JP G31 1</td><td>W.-M. Yao et al.</td><td>(PDG Collab.)</td></tr><tr><td>COAN</td><td>04</td><td>PRL 92 232001</td><td>T.E. Coan et al.</td><td>(CLEO Collab.)</td></tr><tr><td>GOMEZ-DUM.</td><td>04</td><td>PR D69 073002</td><td>D. Gomez Dumm, A. Pich, J. Portoles</td><td></td></tr><tr><td>SALVINI</td><td>04</td><td>PRL C35 21</td><td>P. Salvini et al.</td><td>(OBELIX Collab.)</td></tr><tr><td>BRIERE</td><td>03</td><td>PRL 90 181802</td><td>R. A. Briere et al.</td><td>(CLEO Collab.)</td></tr><tr><td>CHUNG</td><td>02</td><td>PR D65 072001</td><td>S.U. Chung et al.</td><td>(BNL E852 Collab.)</td></tr><tr><td>DRUTSKOY</td><td>02</td><td>PRL B542 171</td><td>A. Drutskoy et al.</td><td>(BELLE Collab.)</td></tr><tr><td>BARBERIS</td><td>01</td><td>PL B507 14</td><td>D. Barberis et al.</td><td>(CLEO Collab.)</td></tr><tr><td>ASNER</td><td>00</td><td>PR D61 012002</td><td>D.M. Asner et al.</td><td>(CLEO Collab.)</td></tr><tr><td>AKHMETSHIN</td><td>99E</td><td>PL B466 392</td><td>R.R. Akhmetshin et al.</td><td>(Novosibirsk. CMD-2 Collab.)</td></tr><tr><td>BARATE</td><td>99R</td><td>EPJ C11 599</td><td>R. Barate et al.</td><td>(ALEPH Collab.)</td></tr><tr><td>BONDAR</td><td>99</td><td>PL B466 403</td><td>A.E. Bondar et al.</td><td>(Novosibirsk. CMD-2 Collab.)</td></tr><tr><td>ABREU</td><td>98G</td><td>PL B426 411</td><td>P. Abreu et al.</td><td>(DELPHI Collab.)</td></tr><tr><td>BARATE</td><td>98R</td><td>EPJ C4 409</td><td>R. Barate et al.</td><td>(ALEPH Collab.)</td></tr><tr><td>BARBERIS</td><td>98B</td><td>PL B422 399</td><td>D. Barberis et al.</td><td>(WA 102 Collab.)</td></tr><tr><td>ACKERSTAFF</td><td>97R</td><td>ZPHY C75 593</td><td>K. Ackerstaff et al.</td><td>(OPAL Collab.)</td></tr><tr><td>BUSKULIC</td><td>96</td><td>ZPHY C70 579</td><td>D. Buskulic et al.</td><td>(ALEPH Collab.)</td></tr><tr><td>AKERS</td><td>95P</td><td>ZPHY C67 45</td><td>R. Akers et al.</td><td>(OPAL Collab.)</td></tr><tr><td>SHALM</td><td>94</td><td>PR D50 43</td><td>M.S. Alam et al.</td><td>(CLEO Collab.)</td></tr><tr><td>ALBRECHT</td><td>93C</td><td>ZPHY C58 61</td><td>H. Albrecht et al.</td><td>(ARGUS Collab.)</td></tr><tr><td>DECKER</td><td>93A</td><td>ZPHY C58 445</td><td>R. Decker et al.</td><td></td></tr><tr><td>ANDO</td><td>92</td><td>ZPHY C29 496</td><td>A. Ando et al.</td><td>(KEK, KYOT, NIRS, SAGA+)</td></tr><tr><td>KUHN</td><td>92</td><td>ZPHY C56 661</td><td>J.H. Kuhn, E. Mirkes</td><td></td></tr><tr><td>IVANOV</td><td>91</td><td>ZPHY C49 563</td><td>Y.P. Ivanov, A.A. Osipov, M.K. Volkov</td><td>(JINR)</td></tr><tr><td>ARMSTRONG</td><td>90</td><td>ZPHY C48 213</td><td>T.A. Armstrong, M. Benayoun, W. Beusch (WA76 Coll.)</td><td></td></tr><tr><td>FEINDT</td><td>90</td><td>ZPHY C48 681</td><td>M. Feindt</td><td>(HAMB)</td></tr><tr><td>KUHN</td><td>90</td><td>ZPHY C48 445</td><td>J.H. Kuhn et al.</td><td>(MPIM)</td></tr><tr><td>ISGUR</td><td>89</td><td>PL D39 1357</td><td>N. Isgur, C. J. Morningstar, C. Reader</td><td>(NTFO)</td></tr><tr><td>BOWLER</td><td>88</td><td>PL B209 99</td><td>M.G. Bowler</td><td>(OXF)</td></tr><tr><td>BAND</td><td>87</td><td>PL B198 297</td><td>H.R. Band et al.</td><td>(MAC Collab.)</td></tr><tr><td>TORNQVIST</td><td>87</td><td>ZPHY C36 695</td><td>N.A. Tornqvist</td><td>(HELS)</td></tr><tr><td>ALBRECHT</td><td>86B</td><td>ZPHY C33 7</td><td>H. Albrecht et al.</td><td>(ARGUS Collab.)</td></tr><tr><td>RUCKSTUHL</td><td>86</td><td>PL 56 2132</td><td>W. Ruckstuhl et al.</td><td>(DLFECO Collab.)</td></tr><tr><td>SCHMIDKE</td><td>86</td><td>PL 57 527</td><td>M.G. Schmidke et al.</td><td>(Mark II Collab.)</td></tr><tr><td>BELLINI</td><td>85</td><td>SJNP 41 781</td><td>D. Bellini et al.</td><td></td></tr><tr><td>ZIELINSKI</td><td>84C</td><td>PR 52 1195</td><td>Translated from YAF 41 1223.</td><td></td></tr><tr><td>LONGACRE</td><td>82</td><td>PR D26 82</td><td>M. Zielinski et al.</td><td>(ROCH, MINN, FNAL)</td></tr><tr><td>LONGACRE</td><td>81</td><td>PR 54 680</td><td>R.S. Longacre</td><td>(BNL)</td></tr><tr><td>DANKOWY...</td><td>82</td><td>PR 58 580</td><td>J.A. Dankowych et al.</td><td>(TNTO, BNL, CRL+)</td></tr><tr><td>DAUM</td><td>81B</td><td>NP B182 269</td><td>C. Daum et al.</td><td>(AMST, CERN, CRAC, MPIM+)</td></tr><tr><td>DAUM</td><td>80</td><td>PL 89B 281</td><td>C. Daum et al.</td><td>(AMST, CERN, CRAC, MPIM+)</td></tr><tr><td>GAVILLET</td><td>77</td><td>PL 89B 119</td><td>P. Gavillet et al.</td><td>(AMST, CERN, NJUM+)</td></tr><tr><td>BOWLER</td><td>75</td><td>NP B97 227</td><td>M.G. Bowler et al.</td><td>(OXFTP, DARE)</td></tr></table>

f₂(1270)

$$f_2(JPC) = 0^{+}(2^{++})$$

f₂(1270) T-MATRIX POLE √s

Note that Γ = -2 Im(√s).

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>(1260-1283) - i (90-110) OUR ESTIMATE</td><td></td><td></td><td></td></tr><tr><td>(1268 ± 8) - i (101 ± 6)</td><td>RODAS</td><td>22</td><td>RVUE</td><td>J/ψ(1S) → γ (ππ, K<sup>-</sup>K<sup>+</sup>)</td></tr><tr><td>(1263.3 ± 0.2 ± 1.5) - i<br>(96.9 ± 0.2 ± 0.8)</td><td>ALBRECHT</td><td>20</td><td>RVUE</td><td>p̄p → π<sup>0</sup>π<sup>0</sup>η, π<sup>0</sup>ηη, π<sup>0</sup>K<sup>+</sup>K<sup>-</sup></td></tr><tr><td>(1270 ± 8) - i (97 ± 8)</td><td>1 ANISOVICH</td><td>09</td><td>RVUE</td><td>0.0 p̄p, πN</td></tr><tr><td>(1278 ± 5) - i (102 ± 10)</td><td>1 BERTIN</td><td>97c</td><td>OBLX</td><td>0.0 p̄p → π<sup>+</sup>π<sup>-</sup> π<sup>0</sup></td></tr></tbody></table>

¹Amplitude did not include dispersive corrections.

f₂(1270) MASS

<table><thead><tr><th>VALUE (MeV)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>1275.4 ± 0.8 OUR AVERAGE</td><td></td><td></td><td></td></tr><tr><td>1275.8 ± 1.0 ± 0.4</td><td>1 BOGOLYUB...</td><td>13</td><td>SPEC</td><td>π<sup>+</sup>(K<sup>+</sup>, p)A → nγ + X</td></tr><tr><td>1262 ± 1/2 ± 8</td><td>2 ABLIKIM</td><td>06v</td><td>BES2</td><td>e<sup>+</sup> e<sup>-</sup> → J/ψ → γπ<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1275 ± 15</td><td>ABLIKIM</td><td>05</td><td>BES2</td><td>J/ψ → φπ<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1283 ± 5</td><td>ALDE</td><td>98</td><td>GAM4</td><td>100 π<sup>-</sup> p → π<sup>0</sup>π<sup>0</sup> n</td></tr><tr><td>1272 ± 8</td><td>PROKOSHKIN</td><td>94</td><td>GAM2</td><td>38 π<sup>-</sup> p → π<sup>0</sup>π<sup>0</sup> n</td></tr><tr><td>1269.7 ± 5.2</td><td>1 AUGUSTIN</td><td>89</td><td>DM2</td><td>e<sup>+</sup> e<sup>-</sup> → 5π</td></tr><tr><td>1283 ± 8</td><td>3 ALDE</td><td>87</td><td>GAM4</td><td>100 π<sup>-</sup> p → 4π0 n</td></tr><tr><td>1274 ± 5</td><td>3 AUGUSTIN</td><td>87</td><td>GAM2</td><td>e<sup>+</sup> e<sup>-</sup> → γπ<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1283 ± 6</td><td>4 LONGACRE</td><td>86</td><td>MPS</td><td>22 π<sup>-</sup> p → n2K<sup>0</sup>S</td></tr><tr><td>1276 ± 7</td><td>COURAU</td><td>84</td><td>DLCO</td><td>e<sup>+</sup> e<sup>-</sup> → e<sup>+</sup> e<sup>-</sup>π<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1273.3 ± 2.3</td><td>5 CHABAUD</td><td>83</td><td>ASPK</td><td>17 π<sup>0</sup> p polarized</td></tr><tr><td>1280 ± 4</td><td>6 CASON</td><td>82</td><td>STRC</td><td>8 π<sup>+</sup> p → Δ<sup>++</sup>π<sup>0</sup> n</td></tr><tr><td>1281 ± 7</td><td>6 GIDAL</td><td>81</td><td>MRK2</td><td>J/ψ decay</td></tr><tr><td>1282 ± 5</td><td>7 CORDEN</td><td>79</td><td>OMEG</td><td>12-15 π<sup>-</sup> p → n2π</td></tr><tr><td>1269 ± 4</td><td>10k</td><td>75</td><td>NICE</td><td>40 π<sup>-</sup> p → n2π<sup>0</sup></td></tr><tr><td>1272 ± 4</td><td>4600</td><td>74</td><td>DBC</td><td>6 π<sup>+</sup> n → π<sup>+</sup>π<sup>-</sup> p</td></tr><tr><td>1277 ± 4</td><td>5300</td><td>71</td><td>HBC</td><td>7.0 π<sup>+</sup> p</td></tr><tr><td>1283 ± 8</td><td>1 STUNTEBECK</td><td>70</td><td>8 π<sup>-</sup> p, 5.4 π<sup>+</sup> d</td><td></td></tr><tr><td>1265 ± 8</td><td>BOESEBECK</td><td>68</td><td>HBC</td><td>8 π<sup>+</sup> p</td></tr><tr><td>• • • We do not use the following data for averages, fits, limits, etc. • • •</td><td></td><td></td><td></td><td></td></tr><tr><td>1257 ± 6</td><td>8 KLEMPT</td><td>22</td><td>RVUE</td><td>J/ψ(1S) → γπ<sup>0</sup>π<sup>0</sup>, γK<sup>0</sup>SK<sup>0</sup>S</td></tr><tr><td>1263 ± 12</td><td>1 CARVER</td><td>21</td><td>CLAS</td><td>γp → π<sup>0</sup>π<sup>0</sup> p</td></tr><tr><td>1259 ± 4 ± 4</td><td>9.10 DOBBS</td><td>15</td><td></td><td>J/ψ → γπ<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1267 ± 4 ± 3</td><td>1.5k 9.10 DOBBS</td><td>15</td><td></td><td>ψ(2S) → γπ<sup>+</sup>π<sup>-</sup></td></tr><tr><td>1277 ± 6</td><td>11 SCHEGELSKY 06a</td><td>06</td><td>RVUE</td><td>γγ → K<sup>0</sup>K<sup>0</sup>K<sup>0</sup>S</td></tr><tr><td>1251 ± 10</td><td>1 TIKHOMIROV 03</td><td>03</td><td>SPEC</td><td>40.0 π<sup>-</sup> C → K<sup>0</sup>S K<sup>0</sup>S K<sup>0</sup>L X</td></tr><tr><td>1260 ± 10</td><td>12 ALDE</td><td>97</td><td>GAM2</td><td>450 pp → p_f π<sup>0</sup>π<sup>0</sup> π<sup>0</sup></td></tr><tr><td>1278 ± 6</td><td>12 GRYGOREV</td><td>96</td><td>SPEC</td><td>40 π<sup>-</sup> N → K<sup>0</sup>S K<sup>0</sup>S K<sup>0</sup>X</td></tr><tr><td>1262 ± 11</td><td>1 AGUILAR...</td><td>91</td><td>EHS</td><td>400 pp</td></tr></tbody></table>