cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17182/hepdata.142989.v1/t4
title: "Table IV" of "Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p+p collisions at sqrt(s)=62.4 GeV"

description: Cross section of midrapidity charged-hadron production from $p$ + $p$ collisions at $\sqrt{s}$ = 62.4 GeV as a function of $p_T$ for positive and negative hadrons.
description: Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from $p$ + $p$ collisions at $\sqrt{s}$ = 62.4 GeV GeV are presented. The PHENIX measurement of the cross sections for 1.0 &lt; $p_T$ &lt; 4.5 GeV/$c$ are consistent with perturbative QCD calculations at next-to-leading order in the strong-coupling constant, $\alpha_s$. Resummed pQCD calculations including terms with next-to-leading-log accuracy, yielding reduced theoretical uncertainties, also agree with the data. The double-helicity asymmetry, sensitive at leading order to the gluon polarization in a momentum-fraction range of 0.05 $\lesssim$ $x_{gluon}$ $\lesssim$ 0.2, is consistent with recent global parametrizations disfavoring large gluon polarization.
DOI: 10.17182/hepdata.142989.v1/t5
title: "Table V" of "Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p+p collisions at sqrt(s)=62.4 GeV"

description: Double-helicity asymmetries and the statistical uncertainties as a function of $p_T$ for positive and negative inclusive charged hadrons from $p$ + $p$ collisions at $\sqrt{s}$ = 62.4 GeV.
description: Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from $p$ + $p$ collisions at $\sqrt{s}$ = 62.4 GeV GeV are presented. The PHENIX measurement of the cross sections for 1.0 &lt; $p_T$ &lt; 4.5 GeV/$c$ are consistent with perturbative QCD calculations at next-to-leading order in the strong-coupling constant, $\alpha_s$. Resummed pQCD calculations including terms with next-to-leading-log accuracy, yielding reduced theoretical uncertainties, also agree with the data. The double-helicity asymmetry, sensitive at leading order to the gluon polarization in a momentum-fraction range of 0.05 $\lesssim$ $x_{gluon}$ $\lesssim$ 0.2, is consistent with recent global parametrizations disfavoring large gluon polarization.
DOI: 10.17182/hepdata.143005.v1/t1
title: "Figure 1a-1" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: Invariant $\pi^0$ yields in central Cu+Cu collisions and invariant $\pi^0$ cross sections in $p$+$p$ collisions at $\sqrt{s_{NN}}$ = 22.4 GeV. The error (tot.) includes the quadratic sum of the statistical and total systematic uncertainties.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t2
title: "Figure 1a-2" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: Invariant $\pi^0$ yields in central Cu+Cu collisions and invariant $\pi^0$ cross sections in $p$+$p$ collisions at $\sqrt{s_{NN}}$ = 62.4 GeV. The error (tot.) includes the quadratic sum of the statistical and total systematic uncertainties.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t3
title: "Figure 1a-3" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: Invariant $\pi^0$ yields in central Cu+Cu collisions and invariant $\pi^0$ cross sections in $p$+$p$ collisions at $\sqrt{s_{NN}}$ = 200 GeV. The error (tot.) includes the quadratic sum of the statistical and total systematic uncertainties.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t4
title: "Figure 2a" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: Measured $\pi^0$ $R_{AA}$ as a function of $p_T$ for the 0-10% most central collisions at $\sqrt{s_{NN}}$ = 22.4 GeV in comparison to a jet quenching calculation. The error (tot.) includes the quadratic sum of the statistical uncertainties and the point-to-point uncorrelated and correlated systematic uncertainties.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t5
title: "Figure 2b" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: Measured $\pi^0$ $R_{AA}$ as a function of $p_T$ for the 0-10% most central collisions at $\sqrt{s_{NN}}$ = 62.4 GeV in comparison to a jet quenching calculation. The error (tot.) includes the quadratic sum of the statistical uncertainties and the point-to-point uncorrelated and correlated systematic uncertainties.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t6
title: "Figure 2c" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: Measured $\pi^0$ $R_{AA}$ as a function of $p_T$ for the 0-10% most central collisions at $\sqrt{s_{NN}}$ = 200.0 GeV in comparison to a jet quenching calculation. The error (tot.) includes the quadratic sum of the statistical uncertainties and the point-to-point uncorrelated and correlated systematic uncertainties.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t7
title: "Figure 3a" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: The average $R_{AA}$ in the interval 2.5 &lt; $p_T$ &lt; 3.5 GeV/$c$ as a function of centrality for Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4 GeV. The error (sys.) includes the normalization and $$ uncertainties for a typical $N_{coll}$ uncertainty of 12%.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t8
title: "Figure 3b" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: The average $R_{AA}$ in the interval 2.5 &lt; $p_T$ &lt; 3.5 GeV/$c$ as a function of centrality for Cu+Cu collisions at $\sqrt{s_{NN}}$ = 62.4 GeV. The error (sys.) includes the normalization and $$ uncertainties for a typical $N_{coll}$ uncertainty of 12%.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143005.v1/t9
title: "Figure 3c" of "Onset of $\pi^0$ Suppression Studied in Cu$+$Cu Collisions at $\sqrt{s_{NN}}=$22.4, 62.4, and 200 GeV"

description: The average $R_{AA}$ in the interval 2.5 &lt; $p_T$ &lt; 3.5 GeV/$c$ as a function of centrality for Cu+Cu collisions at $\sqrt{s_{NN}}$ = 200 GeV. The error (sys.) includes the normalization and $$ uncertainties for a typical $N_{coll}$ uncertainty of 12%.
description: Neutral pion transverse momentum ($p_T$) spectra at mid-rapidity ($|y|$ &lt; 0.35) were measured in Cu+Cu collisions at $\sqrt{s_{NN}}$ = 22.4, 62.4, and 200 GeV. Relative to $\pi^0$ yields in $p$+$p$ collisions scaled by the number of inelastic nucleon-nucleon collisions ($N_{coll}$) at the respective energies, the $\pi^0$ yields for $p_T$ $\ge$ 2 GeV/$c$ in central Cu+Cu collisions at 62.4 and 200 GeV are suppressed, whereas an enhancement is observed at 22.4 GeV. A comparison with a jet quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 GeV and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.
DOI: 10.17182/hepdata.143006.v1/t1
title: "Table 1" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: Glauber quantities ($N_{part}$, $N_{coll}$, $b$) for Au+Au collisions at 200 GeV (PHENIX Run 2007)
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143006.v1/t2
title: "Figure 1" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: Event-plane resolution factors vs. $N_{part}$ for $v_2$ and $v_4$ measurements for the indicated event planes.
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143006.v1/t3
title: "Figure 2" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: Comparison of $v_2$ vs. $N_{part}$ and $v_4$ vs. $N_{part}$ for charged hadrons obtained with several reaction plane detectors for the $p_T$ selections indicated.
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143006.v1/t4
title: "Figure 3a" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: $p_T$ dependence of $v_2$ for charged hadrons for several centrality selections as indicated.
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143006.v1/t5
title: "Figure 3b" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: $p_T$ dependence of $v_4$ for charged hadrons for several centrality selections as indicated.
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143006.v1/t6
title: "Figure 4a-b" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: $v_2$ vs. $N_{part}$ and $v_4$ vs. $N_{part}$ for charged hadrons for several $p_T$ selections as indicated.
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143006.v1/t7
title: "Figure 4c" of "Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sqrt(s_NN) = 200 GeV"

description: The ratio ${v_4}/{(v_2)^2}$ vs. $N_{part}$ for the same $p_T$ selections.
description: Differential measurements of the elliptic ($v_2$) and hexadecapole ($v_4$) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum ($p_T$) and collision centrality or the number of participant nucleons ($N_{part}$) for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $v_{2,4}$ measurements at pseudorapidity $|\eta|$ $\le$ 0.35 obtained with four separate reaction plane detectors positioned in the range 1.0 &lt; $|\eta|$ &lt; 3.9 show good agreement, indicating the absence of significant $\eta$-dependent nonflow perturbations. Sizable values for $v_4(p_T)$ are observed with a ratio ${v_4(p_T,N_{part})}/{v_2^2(p_T,N_{part})}$ $\approx$ 0.8 for 50 $\le$ $N_{part}$ $\le$ 200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For $N_{part}$ $\ge$ 200 this ratio increases up to 1.7 in the most central collisions.
DOI: 10.17182/hepdata.143067.v1/t1
title: "Figure 27" of "Dielectron production in Au$+$Au collisions at $\sqrt{s_{NN}}$=200 GeV"

description: Cocktail of hadronic sources for the 2010 run using the PYTHIA generator for the open heavy flavor contributions.
description: We present measurements of $e^+e^−$ production at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The invariant yield is studied within the PHENIX detector acceptance over a wide range of mass ($m_{ee}$ &lt; 5 GeV/$c^2$) and pair transverse momentum ($p_T$ &lt; 5 GeV/$c$), for minimum bias and for five centrality classes. The $e^+e^-$ yield is compared to the expectations from known sources. In the low-mass region ($m_{ee}$ = 0.30 - 0.76 GeV/$c^2$) there is an enhancement that increases with centrality and is distributed over the entire pair $p_T$ range measured. It is significantly smaller than previously reported by the PHENIX experiment and amounts to 2.3 $\pm$ 0.4(stat) $\pm$ 0.4(syst) $\pm$ 0.2$^{model}$ or to 1.7 $\pm$ 0.3(stat) $\pm$ 0.3(syst) $\pm$ 0.2$^{model}$ for minimum bias collisions when the open-heavy-flavor contribution is calculated with PYTHIA or MC@NLO, respectively. The inclusive mass and $p_T$ distributions as well as the centrality dependence are well reproduced by model calculations where the enhancement mainly originates from the melting of the $\rho$ meson resonance as the system approaches chiral symmetry restoration. In the intermediate-mass region ($m_{ee}$ = 1.2 - 2.8 GeV/$c^2$), the data hint at a significant contribution in addition to the yield from the semileptonic decays of heavy-flavor mesons.