Centrality-dependent direct photon pt spectra in Au+Au collisions at RHIC

Abstract

We calculate the centrality-dependence of transverse momentum ($\pt$) spectra for direct photons in Au+Au collisions at the RHIC energy, based on a realistic data-constrained (3+1) dimensional hydrodynamic description of the expanding hot and dense matter, a reasonable treatment of the propagation of partons and their energy loss in the fluid, and a systematic study of the main sources of direct photons. The resultant $\pt$ spectra agree with recent PHENIX data in a broad $\pt$ range. The competition among the different direct photon sources is investigated at various centralities. Parton energy loss in the plasma is considered for photons from fragmentation and jet photon conversion, which causes about 40% decrease in the total contribution. In the high $\pt$ region, the observed $R_{AA}$ of photons is centrality independent at the accuracy of 5% based on a realistic treatment of energy loss. We also link the different behavior of $R_{AA}$ for central and peripheral collisions, in the low $\pt$ region, to the fact that the plasma in central collisions is hotter compared to peripheral ones.

arXiv comment12 pages, 11 figures

References in corpus (48)

• Radiative energy loss and $p_{\perp }$-broadening of high energy partons in nuclei
• Radiative energy loss of high energy quarks and gluons in a finite volume quark-gluon plasma
• Suppression of Hadrons with Large Transverse Momentum in Central Au+Au Collisions at $sqrt {s sub {sub {NN}}}_ = 130 GeV
• Multiple Collisions and Induced Gluon Bremsstrahlung in QCD
• Disappearance of back-to-back high $p_T$ hadron correlations in central Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV
• Evidence from d+Au measurements for final-state suppression of high $p_T$ hadrons in Au+Au collisions at RHIC
• Gluon Radiation off Hard Quarks in a Nuclear Environment: Opacity Expansion
• Centrality dependence of high pT hadron suppression in Au+Au collisions at sqrt(sNN)=130 GeV
• Hadron production in Au-Au collisions at RHIC
• Energy loss in perturbative QCD
• Collective flow and two-pion correlations from a relativistic hydrodynamic model with early chemical freeze out
• Suppressed pi^0 Production at Large Transverse Momentum in Central Au+Au Collisions at sqrt(s_NN) = 200 GeV
• Photon Emission from Quark-Gluon Plasma: Complete Leading Order Results
• Hadronic dissipative effects on elliptic flow in ultrarelativistic heavy-ion collisions
• Absence of Suppression in Particle Production at Large Transverse Momentum in sqrt(s_NN) = 200 GeV d+Au Collisions
• Photon Emission from Ultrarelativistic Plasmas
• MRST2001: partons and alpha_S from precise deep inelastic scattering and Tevatron jet data
• Transverse Momentum Spectra in Au+Au and d+Au Collisions at $\sqrt{s_{NN}}$=200 GeV and the Pseudorapidity Dependence of High p${}_T$ Suppression
• Hadronic Production of Thermal Photons
• Suppression pattern of neutral pions at high transverse momentum in Au+Au collisions at sqrt(s_NN) = 200 GeV and constraints on medium transport coefficients
• The Search for the Quark-Gluon Plasma
• Centrality Dependence of Direct Photon Production in sqrt(s_NN) = 200 GeV Au+Au Collisions
• Scale evolution of nuclear parton distributions
• Transverse flow and hadro-chemistry in Au+Au collisions at \sqrt{s_{NN}}=200 GeV
• Centrality dependence of charged hadron transverse momentum spectra in d+Au collisions at sqrt(s_NN) = 200 GeV
• Is early thermalization achieved only near midrapidity at RHIC ?
• Inclusive cross section and double helicity asymmetry for π^0 production in p+p collisions at sqrt(s)=200 GeV: Implications for the polarized gluon distribution in the proton
• High energy photons from passage of jets through quark gluon plasma
• Energy Loss of Leading Hadrons and Direct Photon production in Evolving Quark-Gluon Plasma
• Testing the Universality of Fragmentation Functions
• Centrality Dependence of the Charged Particle Multiplicity near Mid-Rapidity in Au+Au Collisions at sqrt(s_NN) = 130 and 200 GeV
• Measurement of direct photon production in p + p collisions at sqrt(s) = 200 GeV
• High-$p_T$ Hadron Spectra, Azimuthal Anisotropy and Back-to-Back Correlations in High-energy Heavy-ion Collisions
• Why the observed jet quenching at RHIC is due to parton energy loss
• Mass ordering of differential elliptic flow and its violation for phi mesons
• Electromagnetic radiation from nuclear collisions at RHIC energies
• Interplay between soft and hard hadronic components for identified hadrons in relativistic heavy ion collisions
• Rho properties in a hot meson gas
• Induced photon emission from quark jets in ultrarelativistic heavy-ion collisions
• Chemical freeze-out temperature in hydrodynamical description of Au+Au collisions at sqrt(s_NN) = 200 GeV
• Back-to-back correlations of high p_T hadrons in relativistic heavy ion collisions
• Elliptic Flow from a Hybrid CGC, Full 3D Hydro and Hadronic Cascade Model
• Centrality Dependence of Direct Photons in Au+Au Collisions at sqrt(s_NN) = 200 GeV
• Systematic Study of High-pT Direct Photon Production with the PHENIX Experiment at RHIC
• Pseudorapidity dependence of parton energy loss in relativistic heavy ion collisions
• Onset of $J/\psi$ Melting in Quark-Gluon Fluid at RHIC
• Jet-fluid string formation and decay in high-energy heavy-ion collisions
• The thermal nature of high p_T photons in high energy nuclear collisions

Cited by in corpus (19)

• Detailed measurement of the e+e- pair continuum in p+p and Au+Au collisions at sqrt(s_NN)=200 GeV and implications for direct photon production
• Heavy Quark Diffusion with Relativistic Langevin Dynamics in the Quark-Gluon Fluid
• QGP formation time and direct photons from heavy ion collisions
• Centrality dependence of the direct photon yield and elliptic flow in heavy-ion collisions at sqrt(s)=200 GeV
• Direct real photons in relativistic heavy ion collisions
• Photon elliptic flow in relativistic heavy-ion collisions: hadronic versus partonic sources
• Photons from the Early Stages of Relativistic Heavy Ion Collisions
• Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider
• Nonequilibrium photon production in partonic transport simulations
• Elliptic flow of thermal photons in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV
• Hard photon flow and photon-photon correlation in intermediate energy heavy-ion collisions
• Direct photons at low transverse momentum -- a QGP signal in pp collisions at LHC
• Production of large transverse momentum dileptons and photons in $pp$, $dA$ and $AA$ collisions by photoproduction processes
• Radial Flow from Electromagnetic Probes and Signal of Quark Gluon Plasma
• Elliptic flow of thermal photons at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV
• Evaluating Results from the Relativistic Heavy Ion Collider with Perturbative QCD and Hydrodynamics
• Direct Photons in Hydrodynamic Modeling of Relativistic Nuclear Collisions
• On QGP Formation in pp Collisions at 7 TeV
• A Theoretic Review of Centrality-Dependent Direct Photon pt spectra in Au+Au Collisions at 200 GeV