Thermal photons as a quark-gluon plasma thermometer reexamined

Shen, Chun; Heinz, Ulrich; Paquet, Jean-François; Gale, Charles

doi:10.1103/PhysRevC.89.044910

Thermal photons as a quark-gluon plasma thermometer reexamined

Journal Article · Mon Apr 28 00:00:00 EDT 2014 · Physical Review C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.89.044910· OSTI ID:1604547

Shen, Chun ^[1]; ^[2]; Paquet, Jean-François ^[3]; Gale, Charles ^[4]

The Ohio State Univ., Columbus, OH (United States); The Ohio State University
The Ohio State Univ., Columbus, OH (United States)
McGill Univ., Montreal, QC (Canada)
McGill Univ., Montreal, QC (Canada); Frankfurt Inst. for Advanced Studies (FIAS), Frankfurt (Germany)

Photons are a penetrating probe of the hot medium formed in heavy-ion collisions, but they are emitted from all collision stages. At photon energies below 2–3 GeV, the measured photon spectra are approximately exponential and can be characterized by their inverse logarithmic slope, often called the “effective temperature” T_eff. Modeling the evolution of the radiating medium hydrodynamically, we analyze the factors controlling the value of the T_effand how it is related to the evolving true temperature T of the fireball. We find that at the energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider most photons are emitted from fireball regions with T ~ T_c near the quark-hadron phase transition, but that their effective temperature is significantly enhanced by strong radial flow. Although a very hot, high-pressure early collision stage is required for generating this radial flow, we demonstrate that the experimentally measured large effective photon temperatures T_eff > T_c, taken alone, do not prove that any electromagnetic radiation was actually emitted from regions with true temperatures well above T_c. We explore tools that can help to provide additional evidence for the relative weight of photon emission from the early quark-gluon and late hadronic phases. We find that the recently measured centrality dependence of the total thermal photon yield requires a larger contribution from late emission than presently encoded in our hydrodynamic model.

View Accepted Manuscript (DOE)

Research Organization:: The Ohio State Univ., Columbus, OH (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)

Grant/Contract Number:: SC0004104; SC0004286

OSTI ID:: 1604547

Journal Information:: Physical Review C, Nuclear Physics, Journal Name: Physical Review C, Nuclear Physics Journal Issue: 4 Vol. 89; ISSN 0556-2813; ISSN PRVCAN

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

References (59)

Temperature measurement of quark-gluon plasma formed in high energy nucleus-nucleus collisions Kajantie, K.; Miettinen, H. I. Zeitschrift f�r Physik C Particles and Fields, Vol. 9, Issue 4 https://doi.org/10.1007/BF01548770	journal	December 1981
Perturbative approach to some one-dimensional many-body problems. I: Discussion of the Rayleigh-Schrödinger and Brillouin-Wigner series for the Sutherland model Levi, D.; Ragnisco, O. Il Nuovo Cimento B Series 11, Vol. 34, Issue 2 https://doi.org/10.1007/BF02728616	journal	August 1976
How robust is a thermal photon interpretation of the ALICE low-p T data? Klasen, M.; Klein-Bösing, C.; König, F. Journal of High Energy Physics, Vol. 2013, Issue 10 https://doi.org/10.1007/JHEP10(2013)119	journal	October 2013
Quark-gluon plasma and hadronic production of leptons, photons and psions Shuryak, E. V. Physics Letters B, Vol. 78, Issue 1 https://doi.org/10.1016/0370-2693(78)90370-2	journal	September 1978
Elliptic Flow of Thermal Photons/Dileptons Heinz, U.; Chatterjee, R.; Frodermann, E. Nuclear Physics A, Vol. 783, Issue 1-4 https://doi.org/10.1016/j.nuclphysa.2006.11.090	journal	February 2007
QCD equation of state and hadron resonance gas Huovinen, Pasi; Petreczky, Péter Nuclear Physics A, Vol. 837, Issue 1-2 https://doi.org/10.1016/j.nuclphysa.2010.02.015	journal	June 2010
Measurement of Direct Photons in pp and Pb–Pb Collisions with ALICE Wilde, Martin Nuclear Physics A, Vol. 904-905 https://doi.org/10.1016/j.nuclphysa.2013.02.079	journal	May 2013
The QCD transition temperature: Results with physical masses in the continuum limit Aoki, Y.; Fodor, Z.; Katz, S. D. Physics Letters B, Vol. 643, Issue 1 https://doi.org/10.1016/j.physletb.2006.10.021	journal	November 2006
Suppression of elliptic flow in a minimally viscous quark–gluon plasma Song, Huichao; Heinz, Ulrich Physics Letters B, Vol. 658, Issue 5 https://doi.org/10.1016/j.physletb.2007.11.019	journal	January 2008
Hydrodynamic elliptic and triangular flow in Pb–Pb collisions at sNN=2.76A TeV Qiu, Zhi; Shen, Chun; Heinz, Ulrich Physics Letters B, Vol. 707, Issue 1 https://doi.org/10.1016/j.physletb.2011.12.041	journal	January 2012
Photon production from non-equilibrium QGP in heavy ion collisions Gelis, F.; Niemi, H.; Ruuskanen, P. V. Journal of Physics G: Nuclear and Particle Physics, Vol. 30, Issue 8 https://doi.org/10.1088/0954-3899/30/8/053	journal	July 2004
EPS09 — A new generation of NLO and LO nuclear parton distribution functions Eskola, K. J.; Paukkunen, H.; Salgado, C. A. Journal of High Energy Physics, Vol. 2009, Issue 04 https://doi.org/10.1088/1126-6708/2009/04/065	journal	April 2009
Measurement of Direct-Photon Elliptic Flow in Pb-Pb Collisions at = 2.76 TeV Lohner, Daniel Journal of Physics: Conference Series, Vol. 446 https://doi.org/10.1088/1742-6596/446/1/012028	journal	September 2013
Photon emission from hot hadronic matter described by an effective chiral Lagrangian Song, Chungsik Physical Review C, Vol. 47, Issue 6 https://doi.org/10.1103/PhysRevC.47.2861	journal	June 1993
Parton equilibration in relativistic heavy ion collisions Biró, T. S.; van Doorn, E.; Müller, B. Physical Review C, Vol. 48, Issue 3 https://doi.org/10.1103/PhysRevC.48.1275	journal	September 1993
Collective flow and two-pion correlations from a relativistic hydrodynamic model with early chemical freeze-out Hirano, Tetsufumi; Tsuda, Keiichi Physical Review C, Vol. 66, Issue 5 https://doi.org/10.1103/PhysRevC.66.054905	journal	November 2002
Hadronic production of thermal photons Turbide, Simon; Rapp, Ralf; Gale, Charles Physical Review C, Vol. 69, Issue 1 https://doi.org/10.1103/PhysRevC.69.014903	journal	January 2004
Energy loss of leading hadrons and direct photon production in evolving quark-gluon plasma Turbide, Simon; Gale, Charles; Jeon, Sangyong Physical Review C, Vol. 72, Issue 1 https://doi.org/10.1103/PhysRevC.72.014906	journal	July 2005
Electromagnetic radiation from nuclear collisions at ultrarelativistic energies Turbide, Simon; Gale, Charles; Frodermann, Evan Physical Review C, Vol. 77, Issue 2 https://doi.org/10.1103/PhysRevC.77.024909	journal	February 2008
Causal viscous hydrodynamics in 2 + 1 dimensions for relativistic heavy-ion collisions Song, Huichao; Heinz, Ulrich Physical Review C, Vol. 77, Issue 6 https://doi.org/10.1103/PhysRevC.77.064901	journal	June 2008
Multiplicity scaling in ideal and viscous hydrodynamics Song, Huichao; Heinz, Ulrich Physical Review C, Vol. 78, Issue 2 https://doi.org/10.1103/PhysRevC.78.024902	journal	August 2008
Jet energy loss, photon production, and photon-hadron correlations at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) Qin, Guang-You; Ruppert, Jörg; Gale, Charles Physical Review C, Vol. 80, Issue 5 https://doi.org/10.1103/PhysRevC.80.054909	journal	November 2009
Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au + Au collisions at s NN = 200 GeV Shen, Chun; Heinz, Ulrich; Huovinen, Pasi Physical Review C, Vol. 82, Issue 5 https://doi.org/10.1103/PhysRevC.82.054904	journal	November 2010
Enhancement of thermal photon production in event-by-event hydrodynamics Chatterjee, Rupa; Holopainen, Hannu; Renk, Thorsten Physical Review C, Vol. 83, Issue 5 https://doi.org/10.1103/PhysRevC.83.054908	journal	May 2011
Hadron spectra and elliptic flow for 200 A GeV Au + Au collisions from viscous hydrodynamics coupled to a Boltzmann cascade Song, Huichao; Bass, Steffen A.; Heinz, Ulrich Physical Review C, Vol. 83, Issue 5 https://doi.org/10.1103/PhysRevC.83.054910	journal	May 2011
Radial and elliptic flow in Pb + Pb collisions at energies available at the CERN Large Hadron Collider from viscous hydrodynamics Shen, Chun; Heinz, Ulrich; Huovinen, Pasi Physical Review C, Vol. 84, Issue 4 https://doi.org/10.1103/PhysRevC.84.044903	journal	October 2011
Thermal photons and collective flow at energies available at the BNL Relativistic Heavy-Ion Collider van Hees, Hendrik; Gale, Charles; Rapp, Ralf Physical Review C, Vol. 84, Issue 5 https://doi.org/10.1103/PhysRevC.84.054906	journal	November 2011
Viscous photons in relativistic heavy ion collisions Dion, Maxime; Paquet, Jean-François; Schenke, Björn Physical Review C, Vol. 84, Issue 6 https://doi.org/10.1103/PhysRevC.84.064901	journal	December 2011
Erratum: Hadron spectra and elliptic flow for 200 A GeV Au+Au collisions from viscous hydrodynamics coupled to a Boltzmann cascade [Phys. Rev. C 83 , 054910 (2011)] Song, Huichao; Bass, Steffen A.; Heinz, Ulrich Physical Review C, Vol. 86, Issue 5 https://doi.org/10.1103/PhysRevC.86.059903	journal	November 2012
Elliptic flow of thermal photons from an event-by-event hydrodynamic model Chatterjee, Rupa; Holopainen, Hannu; Helenius, Ilkka Physical Review C, Vol. 88, Issue 3 https://doi.org/10.1103/PhysRevC.88.034901	journal	September 2013
Centrality dependence of the direct photon yield and elliptic flow in heavy-ion collisions at s N N = 200 GeV Linnyk, O.; Cassing, W.; Bratkovskaya, E. L. Physical Review C, Vol. 89, Issue 3 https://doi.org/10.1103/PhysRevC.89.034908	journal	March 2014
Diagnosing quark matter by measuring the total entropy and the photon or dilepton emission rates Hwa, Rudolph C.; Kajantie, K. Physical Review D, Vol. 32, Issue 5 https://doi.org/10.1103/PhysRevD.32.1109	journal	September 1985
Transverse-flow effects in dilepton emission Kajantie, K.; Kataja, M.; McLerran, L. Physical Review D, Vol. 34, Issue 3 https://doi.org/10.1103/PhysRevD.34.811	journal	August 1986
High-energy photons from quark-gluon plasma versus hot hadronic gas Kapusta, Joseph; Lichard, Peter; Seibert, David Physical Review D, Vol. 44, Issue 9 https://doi.org/10.1103/PhysRevD.44.2774	journal	November 1991
Erratum: High-energy photons from quark-gluon plasma versus hot hadronic gas Kapusta, Joseph; Lichard, Peter; Seibert, David Physical Review D, Vol. 47, Issue 9 https://doi.org/10.1103/PhysRevD.47.4171	journal	May 1993
Recent critical study of photon production in hadronic collisions Aurenche, P.; Guillet, J. Ph.; Pilon, E. Physical Review D, Vol. 73, Issue 9 https://doi.org/10.1103/PhysRevD.73.094007	journal	May 2006
Chiral and deconfinement aspects of the QCD transition Bazavov, A.; Bhattacharya, T.; Cheng, M. Physical Review D, Vol. 85, Issue 5 https://doi.org/10.1103/PhysRevD.85.054503	journal	March 2012
Enhanced Production of Direct Photons in Au + Au Collisions at s N N = 200 GeV and Implications for the Initial Temperature Adare, A.; Afanasiev, S.; Aidala, C. Physical Review Letters, Vol. 104, Issue 13 https://doi.org/10.1103/PhysRevLett.104.132301	journal	March 2010
200 A GeV Au + Au Collisions Serve a Nearly Perfect Quark-Gluon Liquid Song, Huichao; Bass, Steffen A.; Heinz, Ulrich Physical Review Letters, Vol. 106, Issue 19 https://doi.org/10.1103/PhysRevLett.106.192301	journal	May 2011
Observation of Direct-Photon Collective Flow in Au + Au Collisions at s N N = 200 GeV Adare, A.; Afanasiev, S.; Aidala, C. Physical Review Letters, Vol. 109, Issue 12 https://doi.org/10.1103/PhysRevLett.109.122302	journal	September 2012
Erratum: 200 A GeV Au + Au Collisions Serve a Nearly Perfect Quark-Gluon Liquid [Phys. Rev. Lett. 106 , 192301 (2011)] Song, Huichao; Bass, Steffen A.; Heinz, Ulrich Physical Review Letters, Vol. 109, Issue 13 https://doi.org/10.1103/PhysRevLett.109.139904	journal	September 2012
High-Energy Photons from Passage of Jets through Quark-Gluon Plasma Fries, Rainer J.; Müller, Berndt; Srivastava, Dinesh K. Physical Review Letters, Vol. 90, Issue 13 https://doi.org/10.1103/PhysRevLett.90.132301	journal	March 2003
Elliptic Flow of Thermal Photons in Relativistic Nuclear Collisions Chatterjee, Rupa; Frodermann, Evan S.; Heinz, Ulrich Physical Review Letters, Vol. 96, Issue 20 https://doi.org/10.1103/PhysRevLett.96.202302	journal	May 2006
Suppression of elliptic flow in a minimally viscous quark-gluon plasma Song, Huichao; Heinz, Ulrich W. arXiv https://doi.org/10.48550/arxiv.0709.0742	text	January 2007
Causal viscous hydrodynamics in 2+1 dimensions for relativistic heavy-ion collisions Song, Huichao; Heinz, Ulrich W. arXiv https://doi.org/10.48550/arxiv.0712.3715	text	January 2007
Multiplicity scaling in ideal and viscous hydrodynamics Song, Huichao; Heinz, Ulrich W. arXiv https://doi.org/10.48550/arxiv.0805.1756	text	January 2008
EPS09 - a New Generation of NLO and LO Nuclear Parton Distribution Functions Eskola, K. J.; Paukkunen, H.; Salgado, C. A. arXiv https://doi.org/10.48550/arxiv.0902.4154	text	January 2009
Hadron spectra and elliptic flow for 200 A GeV Au+Au collisions from viscous hydrodynamics coupled to a Boltzmann cascade Song, Huichao; Bass, Steffen A.; Heinz, Ulrich W. arXiv https://doi.org/10.48550/arxiv.1101.4638	text	January 2011
Hydrodynamic elliptic and triangular flow in Pb-Pb collisions at sqrt(s)=2.76ATeV Qiu, Zhi; Shen, Chun; Heinz, Ulrich W. arXiv https://doi.org/10.48550/arxiv.1110.3033	text	January 2011
The chiral and deconfinement aspects of the QCD transition Bazavov, A.; Bhattacharya, T.; Cheng, M. arXiv https://doi.org/10.48550/arxiv.1111.1710	text	January 2011
Measurement of Direct-Photon Elliptic Flow in Pb-Pb Collisions at sqrt(NN) = 2.76 TeV Lohner, Daniel arXiv https://doi.org/10.48550/arxiv.1212.3995	text	January 2012
The QCD transition temperature: results with physical masses in the continuum limit Aoki, Y.; Fodor, Z.; Katz, S. D. arXiv https://doi.org/10.48550/arxiv.hep-lat/0609068	text	January 2006
Hadronic Production of Thermal Photons Turbide, Simon; Rapp, Ralf; Gale, Charles arXiv https://doi.org/10.48550/arxiv.hep-ph/0308085	text	January 2003
A new critical study of photon production in hadronic collisions Aurenche, Patrick; Fontannaz, Michel; Guillet, Jean-Philippe arXiv https://doi.org/10.48550/arxiv.hep-ph/0602133	text	January 2006
Collective flow and two-pion correlations from a relativistic hydrodynamic model with early chemical freeze out Hirano, Tetsufumi; Tsuda, Keiichi arXiv https://doi.org/10.48550/arxiv.nucl-th/0205043	text	January 2002
High energy photons from passage of jets through quark gluon plasma Fries, R. J.; Müller, B.; Srivastava, D. K. arXiv https://doi.org/10.48550/arxiv.nucl-th/0208001	text	January 2002
Photon production from non-equilibrium QGP in heavy ion collisions Gelis, F.; Niemi, H.; Ruuskanen, P. V. arXiv https://doi.org/10.48550/arxiv.nucl-th/0403040	text	January 2004
Parton Equilibration in Relativistic Heavy Ion Collisions Biro, T. S.; van Doorn, E.; Mueller, B. arXiv https://doi.org/10.48550/arxiv.nucl-th/9303004	text	January 1993
Rapp, R. Acta Physica Polonica B, Vol. 42, Issue 12 https://doi.org/10.5506/APhysPolB.42.2823	journal	January 2011

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