# Presentation: 102172

## Charmed Hadron Spectroscopy At

- Robert K. Kutschke
- Fermilab
- HQ2K October 11, 2000

- Introduction
- C , C*
- c*
- D**
- DS**.

## 

- At Fermilab
- BeO     charm

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## FOCUS: The Successor to  E687

- Segmented BeO Target interleaved with SMDs.
- Upgraded:
- EM Calorimetry.
- Cerenkov system.
- Muon ID capability.
- Data taken in 1996-1997.
- More than 10 times the Luminosity
- >106  reconstructed  “Golden Mode” Decays:        D0K-K-and  D+K-

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Candidate Driven Vertexing

- Find charm candidate: good vertex, good particle ID.
- Seed primary vertex finder with the charm candidate.
- Require isolated secondary.  One measure: L/L> cut.
- Add tracks from primary to form ccombinations.

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Some Charmed Baryons:

- cdd

- cud

- cuu

- c*+

- c0

- c*++

- JP

-  3/2-

- c(2625)

- c+

- c*0

- 1/2+

- c++

- c+

- c(2593)

- c*c

- c(*) c

- cud

- JP

-  3/2+

-  1/2-

- P-Wave Baryon

- c*c

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Selection of cfor c++and c0Studies

- 4000

- 2000

- 3000

- 1000

- 5000

- Entries / 5 MeV/c2

- 2.1

- 2.2

- 2.3

- 2.4

- M(p+K-)

- (GeV/c2)

- Yield=12410  180

- S/B  = 1.7

- 7.890.11     MeV/c2

- Cut  2

- Sidebands

- FOCUS

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

##  c++and c0Masses

- M(c0) – M(c+) =
- 167.38  0.21 MeV/c2

- M(c++) – M(c+) =
- 167.35  0.19 MeV/c2

-  c++and c0Masses

- C++C+ 

- C0C+ 

- Entries / 500 KeV/c2

- Yield = 362  36

- Yield = 461  39

- 0.15

- 0.17

- 0.19

- (GeV/c2)

- 0.15

- 0.17

- 0.19

- (GeV/c2)

- M(C+) – MC+

- FOCUS

- 60

- 40

- 20

- 60

- 40

- 20

- ( CLEO 2.5 ICHEP 2000

- 167.20.10.2 MeV/c2 )

- ( CLEO 2.5 ICHEP 2000

- 167.40.10.2 MeV/c2 )

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Systematic Errors

|  Source |        Systematic Error (MeV/c2) |  |  |
| --- | --- | --- | --- |
|  | c++c+ | c0c+ | c++c0 |
| Momentum Scale | 0.05 | 0.05 | 0.00 |
| Fitting | 0.02 | 0.06 | 0.04 |
| Recon. Bias | 0.04 | 0.04 | 0.00 |
| Analysis Cuts | 0.10 | 0.10 | 0.10 |
| Total  | 0.12 | 0.13 | 0.11 |

- M(c++) – Mc0=-0.03  0.28  0.11  MeV/c2

- Phys. Lett. B488, 218-224, 2000.

- M(c0) – M(c+ ) =  167.38  0.21  0.13  MeV/c2

- M(c  ) – M(c ) =  167.35 0.19  0.12  MeV/c2

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Slide 9

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Observation of  c+  c+0

- (GeV/c2)

- 100

- 200

- 150

-  50

- 0.2

- 0.4

- 0.16

- 0.20

- 0.3

- 0.18

- 0.14

- Mc+ – Mc+

- 20

- 80

- 60

- 40

- N / 1 MeV/c2

- N / 3 MeV/c2

- Mc+ –Mc+168.0   1.0   0.3  MeV/c2

- ( CLEO hep_ex/0007041: Mc+ – Mc+166.4   0.2   0.3  MeV/c2 )

- Mc+ –Mc00.6   1.0   0.3  MeV/c2

- 

- 

- 

- 

- 

- 

- Yield =118  40

- 

- 0Reconstructed in EMCAL.

- Preliminary

- FOCUS

-  

- 3.040.84 MeV/c2

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Isospin Mass Differences

|  | Mass Difference (MeV/c2) |  |  |  |
| --- | --- | --- | --- | --- |
| Particles | PDG 1998 | CLEO 2.5 | FOCUS |  |
|   N-P | 1.293318 ± 0.000009 |  |  |  |
|  | 2.6 ± 0.4 |  |  |  |
|  | 8.08 ± 0.08 |  |  |  |
|  | 6.4 ± 0.6 |  |  |  |
| cc | 4.7 ± 0.6 |  |  |  |
| cc | -0.57 ±  0.23 |  | 0.03±0.28±0.11 |  |
| cc | -1.4 ±  0.6 | 0.7 ± 0.5 | -0.6±1.0±0.3 |  |

- Preliminary

- Theory has canceling contributions: quark masses,  strong potential, Coulomb interaction, hyperfine         ( EM + QCD ).

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Natural Widths  (MeV/c2)

- c02.58  0.79

- c++2.53  0.77

- 0.20

- 0.18

- 0.16

- 0.14

- 0.16

- 0.14

- 0.18

- (GeV/c2)

- 0.20

- 80

- 60

- 40

- 20

- 80

- 60

- 40

- 20

- Mc+ – Mc

- Mc+ – Mc

- Signal Shape: BW convoluted with a gaussian.

- Preliminary

- MeV/c2

- Entries / 0.5 MeV/c2

- FOCUS

- ( CLEO 2.5 ICHEP 2000:  MeV/c2 )

- MeV/c2

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## c++and c0

| Theoretical Predictions |  |  |  |
| --- | --- | --- | --- |
| Author ‡ | (MeV/c2) |  |  |
|  | c0  | c++ |  |
| Ivanov | 2.65 ± 0.19 | 2.85 ± 0.19 |  |
| Tawfig | 1.57 | 1.64 |  |
| Huang | 2.4 | 2.5 |  |
| Pirjol | 1.0 - 3.0 | 1.1 - 3.1 |  |
| Rosner | 1.32 ± 0.04 | 1.32 ± 0.04 |  |
| ‡ References at end of talk. |  |  |  |
| Focus Preliminary Results |  |  |  |
|  | 2.58 ± 0.79                |  | 2.53 ± 0.77        |

- +0.51

-  -0.56

- +0.51

-  -0.55

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Observation of c*++ and c*0 

- 0.30

- 0.25

- 0.15

- 0.20

- 0.30

- 0.20

- 0.25

- 0.15

- (GeV/c2)

- Mc+ – Mc

- Mc+ – Mc

-  300

-  200

-  100

-  300

-  200

-  100

- Entries / 1.0 MeV/c2

- Mc0232.7  1.2 MeV/c2

- Mc++234.21.5 MeV/c2

- Preliminary

- 9.4  3.7 MeV/c2

- = 23.6  4.5 MeV/c2

- Mc*0Mc*++ = -1.5  1.9 MeV/c2

- Yield = 1284  225

- Yield = 593  146

- 

- 

- FOCUS

- ( CLEO II:  M0=232.61.00.8  M++)

- Stat errs only

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Observation of Excited c States

- (GeV/c2)

- 0.30

- 0.35

- 0.40

- 0.45

- 250

- 200

- 150

- 100

-  50

- M(c+) – M(c+)

- c(2625):
-  M  = 341.6 ± 0.3 MeV/c2

- c(2593):
-  M  = 308.1 ± 0.7 MeV/c2

- Entries / 2 MeV/c2

- Preliminary

- Errors are Stat only.

- FOCUS

- ( PDG 2000: 341.7  0.6 )

- Yield = 371 ± 32

- Yield = 100 ± 20

- ( PDG 2000: 308.9  0.6 )

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## P-Wave Charmed Mesons

- D

- D0*

- D*

- D1

- D2*

- D1

- JP

- 1+

- 0+

- 2+

- 1+

- 0-

- 1-

- jlight

- 1/2

- 1/2

- 3/2

- S-Wave Dominant

- D-Wave Dominant‡

-  O(20) MeV/c2

-  O(200) MeV/c2

- ‡ Except DS1.

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## P-Wave Charmed Mesons

-  L=1 between c and q.
-  For each of  cd,  cu,  cs, expect two doublets:

- Narrow doublet:
-   O( 10 MeV )
-  All observed
- JP = ( 2+, 1+)
-  jlight = 3/2
-  D(*)decay: D wave.

- Broad doublet:
-   O( 100 MeV )
-  One candidate
- JP = ( 1+, 0+)
-  jlight = 1⁄2
-   D(*)decay: S wave.

-  jlight = Slight + L , a good Q number if mC >> QCD
-  Dominant decays: D D*DK,  D*K for cs).
-  Masses within   50 MeV of the mutliplet center. 

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## S-Wave Charm States at FOCUS

- D0  K 

- D0  K 

- D+  K 

- For S/B > 7,

- > 330,000 D candidates

- Entries / 5 MeV/c2

- D*+  D0 

-     K 

-     K

- Entries / 0.5 MeV/c2

- 30000

- 20000

- 10000

- 0.140

- M(D0+)-M(D0)

- (GeV/c2)

- 0.144

- 0.148

- For S/B > 5,

-  70,000 D*+ candidates

- (GeV/c2)

- D+

- D0

- M(Kor K3)

- M(K)

- D*+

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## D0and D+ Mass Distributions

- D0and D+ Mass Distributions

**Wrong sign**

**Wrong sign**

- Feed down from D2*, D1 partial
- reconstruction

- Feed down from D2*, D1 partial
- reconstruction

- M(D0+)-M(D0)+1.8646 (GeV/c2)

- M(D+-)-M(D+)+1.8693 (GeV/c2)

- [  Shorthand: MF(D0)

- MF(D+) ]

- Entries / 10 MeV/c2

- Entries / 10 MeV/c2

- FOCUS

- FOCUS

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Get Feed-down Line Shapes from Monte Carlo

- MC

- MC

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Beyond Signal Region all Shapes are Exponential

- Side band:
- e-2.670.04

- Wrong sign: e-2.380.01

- Right sign:  e-2.350.01

- D2*0     D+-

- Side band:
- e-2.650.03

- Wrong sign: e-2.270.01

- Right sign:   e-2.530.01

- D2*+     Do+

- MF(D0)   (GeV/c2)

- MF(D+)   (GeV/c2)

- Entries / 10 MeV/c2

- Entries / 10 MeV/c2

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

##  Fitting the D0 Mass Distribution  (1)

- Entries / 10 MeV/c2

- =724 MeV/c2

- 2 / dof= 3.1

- MF(D0)        (GeV/c2)

- Fit Results:

- Terms in the Fit:

- Signal: D-wave Rel. BW,   convoluted with a gaussian, = 7 MeV/c2.
- Exponential extrapolated from 2.4 – 4.5 GeV/c2.
- MC D1 Feed-down.
- MC D2  Feed-down

- Get horrible fit!

- FOCUS

-  ( PDG(D2*+) = 25  8 MeV/c2 )

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## D2*  D  Exponential Background Subtracted

- D2*0

- D2*+

- D2*  D  Exponential Background Subtracted

- MF(D0)   (GeV/c2)

- MF(D+)   (GeV/c2)

- Entries / 10 MeV/c2

- Entries / 10 MeV/c2

- FOCUS

- FOCUS

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

##  Fitting the D0 Mass Distribution  (2)

** **Fitting the D0 Mass** **Distribution  (2)

- MF(D0)        (GeV/c2)

- =724 MeV/c2

- 2 / dof= 3.1

- Fit Results:

- Entries / 10 MeV/c2

- MF(D0)        (GeV/c2)

- M=2468.21.5 MeV/c2

- 2 / dof= 1.8

- =    28.6±1.3 MeV/c2

- Add 5th term to the fit: S-wave Rel. BW

- FOCUS

- FOCUS

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Reducing BG from Soft  From D*+ Decays

- Reducing BG from Soft  From D*+ Decays

- M =  2468.5  2.1 MeV/c2
-   =     30.3  3.6 MeV/c2

- D2*+

-  p> 10 GeV/c

- MF(D0)        (GeV/c2)

- Entries / 10 MeV/c2

- FOCUS

- MC

- MC

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Fitting the D+- Mass Distribution

- 2 / dof = 0.9

- MF(D+)        (GeV/c2)

- = 55  3 MeV/c2

- 2  / dof= 2

** ******PDG ( D2*0 ) = 23  5  MeV/c2

- MF(D+)        (GeV/c2)

- Signal + Exp + D1 + D2

- + S-Wave Rel. BW

- Entries / 10 MeV/c2

- Entries / 10 MeV/c2

- =     30.5  1.9 MeV/c2

- M =  2463.5  1.5 MeV/c2

- FOCUS

- FOCUS

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## D2*+   Width 

- D2*+   Width

- D2* Mass and Width Systematics_** **_

- D2*+   Mass

- FOCUS D2*  Results
-          Mass (MeV/c2)           (MeV/c2)
- D2*+   2468.2  1.5  1.4        28.6  1.3  3.8
- D2*0   2463.5  1.5  1.5        30.5  1.9  3.8

- Preliminary

- D2*+ Mass  MeV/c2

- D2*+ Width  MeV/c2

- PDG 2000: M+=24594, M0=2458.92.0, +=258, =235 MeV/c2.

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## D*+- Mass Distribution

- Wrong sign

- D10 Yield = 889  92

- D2*0 Yield =  977  101

- M((D0+))-M(D0)+2.0100

- 2.7

- 2.4

- 2.1

- [  Shorthand: MF(D*+)]

- 800

- 600

- Entries / 10 MeV/c2

- (GeV/c2)

- 200

- 400

- Preliminary

- 1200

- 2.7

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Excited cs Mesons at FOCUS

-  -

- M(D0+)-M(D0)+1.8646

- Entries / 10 MeV/c2

- Fit:         Yield= 744  99
-               M= 2568.1±1.6 MeV/c2
-              = 10 ± 1 MeV/c2

- PDG: M(DS2*)=2573.51.7 MeV/c2

- +

- Wrong sign

- 3.2

- 2.8

- 2.4

- (GeV/c2)

- 400

- 1600

- 1200

- 800

- (DS2*)=15    MeV/c2

- +5

-  -4

- 15

- Entries / 1 MeV/c2

- 25

-  5

- 2.50

- 2.54

- 2.58

- (GeV/c2)

- M(D*+KS0)-M(D*+)+2.0100

- PDG:
- M(DS1) = 2535.35  0.34 MeV/c2

- (DS1) < 2.3  MeV/c2  @ 90% CL

- Fit: Yield= 41  6
-          M = 2535.2 ± 0.4 MeV/c2

- Preliminary

- = 1.3±0.1 MeV/c2

- Stat errors only.   DS1 width consistent with detector resolution.

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## Summary and Conclusions

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke

## References for Theory on Page 13

- M.A. Ivanov et al., Phys. Lett. B442, 435 (1998).
- M.A. Ivanov et al., Phys. Rev. D60, 094002 (1999).
- S. Tawfig et al., Phys. Rev. D58, 054010 (1998).
- M.-Q. Huang et al., Phys. Rev. D52, 3986 (1995).
- D. Pirol and T.-M. Yan, Phys. Rev D56, 5483 (1997).
- J.L. Rosner, Phys. Rev. D52, 6461 (1995).

- Heavy Quarks at Fixed Target, 2000.

- R. K. Kutschke