Advertisement

Holographic photon production in heavy ion collisions

  • Ioannis Iatrakis
  • Elias Kiritsis
  • Chun Shen
  • Di-Lun YangEmail author
Open Access
Regular Article - Theoretical Physics

Abstract

The thermal-photon emission from strongly coupled gauge theories at finite temperature is calculated using holographic models for QCD in the Veneziano limit (V-QCD). The emission rates are then embedded in hydrodynamic simulations combined with prompt photons from hard scattering and the thermal photons from hadron gas to analyze the spectra and anisotropic flow of direct photons at RHIC and LHC. The results from different sources responsible for the thermal photons in QGP including the weakly coupled QGP (wQGP) from perturbative calculations, strongly coupled \( \mathcal{N} \) = 4 super Yang-Mills (SYM) plasma (as a benchmark for reference), and Gubser’s phenomenological holographic model are then compared. It is found that the direct-photon spectra are enhanced in the strongly coupled scenario compared with the ones in the wQGP, especially at high momenta. Moreover, both the elliptic flow and triangular flow of direct photons are amplified at high momenta for V-QCD and the SYM plasma. The results are further compared with experimental observations.

Keywords

AdS-CFT Correspondence Holography and quark-gluon plasmas 

Notes

Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

References

  1. [1]
    C. Gale, Photon Production in Hot and Dense Strongly Interacting Matter, Landolt-Bornstein 23 (2010) 445 [arXiv:0904.2184] [INSPIRE].ADSGoogle Scholar
  2. [2]
    C. Shen, Electromagnetic Radiation from QCD Matter: Theory Overview, Nucl. Phys. A 956 (2016) 184 [arXiv:1601.02563] [INSPIRE].ADSCrossRefGoogle Scholar
  3. [3]
    P.B. Arnold, G.D. Moore and L.G. Yaffe, Photon emission from ultrarelativistic plasmas, JHEP 11 (2001) 057 [hep-ph/0109064] [INSPIRE].
  4. [4]
    P.B. Arnold, G.D. Moore and L.G. Yaffe, Photon emission from quark gluon plasma: Complete leading order results, JHEP 12 (2001) 009 [hep-ph/0111107] [INSPIRE].
  5. [5]
    M. Le Bellac, Thermal Field Theory, Cambridge University Press, Cambridge (1996).CrossRefGoogle Scholar
  6. [6]
    C. Shen, J.-F. Paquet, U. Heinz and C. Gale, Photon Emission from a Momentum Anisotropic quark-gluon Plasma, Phys. Rev. C 91 (2015) 014908 [arXiv:1410.3404] [INSPIRE].ADSGoogle Scholar
  7. [7]
    J. Ghiglieri, J. Hong, A. Kurkela, E. Lu, G.D. Moore and D. Teaney, Next-to-leading order thermal photon production in a weakly coupled quark-gluon plasma, JHEP 05 (2013) 010 [arXiv:1302.5970] [INSPIRE].ADSCrossRefGoogle Scholar
  8. [8]
    A. Amato, G. Aarts, C. Allton, P. Giudice, S. Hands and J.-I. Skullerud, Electrical conductivity of the quark-gluon plasma across the deconfinement transition, Phys. Rev. Lett. 111 (2013) 172001 [arXiv:1307.6763] [INSPIRE].ADSCrossRefGoogle Scholar
  9. [9]
    G. Aarts, C. Allton, A. Amato, P. Giudice, S. Hands and J.-I. Skullerud, Electrical conductivity and charge diffusion in thermal QCD from the lattice, JHEP 02 (2015) 186 [arXiv:1412.6411] [INSPIRE].ADSMathSciNetCrossRefGoogle Scholar
  10. [10]
    J.M. Maldacena, The large-N limit of superconformal field theories and supergravity, Int. J. Theor. Phys. 38 (1999) 1113 [hep-th/9711200] [INSPIRE].MathSciNetCrossRefzbMATHGoogle Scholar
  11. [11]
    S.S. Gubser, I.R. Klebanov and A.M. Polyakov, Gauge theory correlators from noncritical string theory, Phys. Lett. B 428 (1998) 105 [hep-th/9802109] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  12. [12]
    E. Witten, Anti-de Sitter space and holography, Adv. Theor. Math. Phys. 2 (1998) 253 [hep-th/9802150] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  13. [13]
    J. Casalderrey-Solana, H. Liu, D. Mateos, K. Rajagopal and U.A. Wiedemann, Gauge/String Duality, Hot QCD and Heavy Ion Collisions, arXiv:1101.0618 [INSPIRE].
  14. [14]
    S. Caron-Huot, P. Kovtun, G.D. Moore, A. Starinets and L.G. Yaffe, Photon and dilepton production in supersymmetric Yang-Mills plasma, JHEP 12 (2006) 015 [hep-th/0607237] [INSPIRE].ADSCrossRefGoogle Scholar
  15. [15]
    D. Mateos and L. Patino, Bright branes for strongly coupled plasmas, JHEP 11 (2007) 025 [arXiv:0709.2168] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  16. [16]
    A. Parnachev and D.A. Sahakyan, Photoemission with Chemical Potential from QCD Gravity Dual, Nucl. Phys. B 768 (2007) 177 [hep-th/0610247] [INSPIRE].ADSCrossRefGoogle Scholar
  17. [17]
    B. Hassanain and M. Schvellinger, Diagnostics of plasma photoemission at strong coupling, Phys. Rev. D 85 (2012) 086007 [arXiv:1110.0526] [INSPIRE].ADSzbMATHGoogle Scholar
  18. [18]
    B. Hassanain and M. Schvellinger, Plasma photoemission from string theory, JHEP 12 (2012) 095 [arXiv:1209.0427] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  19. [19]
    K.A. Mamo, Enhanced thermal photon and dilepton production in strongly coupled N = 4 SYM plasma in strong magnetic field, JHEP 08 (2013) 083 [arXiv:1210.7428] [INSPIRE].ADSCrossRefGoogle Scholar
  20. [20]
    H.-U. Yee, Flows and polarization of early photons with magnetic field at strong coupling, Phys. Rev. D 88 (2013) 026001 [arXiv:1303.3571] [INSPIRE].ADSGoogle Scholar
  21. [21]
    B. Müller, S.-Y. Wu and D.-L. Yang, Elliptic flow from thermal photons with magnetic field in holography, Phys. Rev. D 89 (2014) 026013 [arXiv:1308.6568] [INSPIRE].ADSGoogle Scholar
  22. [22]
    L. Patino and D. Trancanelli, Thermal photon production in a strongly coupled anisotropic plasma, JHEP 02 (2013) 154 [arXiv:1211.2199] [INSPIRE].ADSCrossRefGoogle Scholar
  23. [23]
    S.-Y. Wu and D.-L. Yang, Holographic Photon Production with Magnetic Field in Anisotropic Plasmas, JHEP 08 (2013) 032 [arXiv:1305.5509] [INSPIRE].ADSCrossRefGoogle Scholar
  24. [24]
    V. Jahnke, A. Luna, L. Patiño and D. Trancanelli, More on thermal probes of a strongly coupled anisotropic plasma, JHEP 01 (2014) 149 [arXiv:1311.5513] [INSPIRE].ADSCrossRefGoogle Scholar
  25. [25]
    R. Baier, S.A. Stricker, O. Taanila and A. Vuorinen, Production of Prompt Photons: Holographic Duality and Thermalization, Phys. Rev. D 86 (2012) 081901 [arXiv:1207.1116] [INSPIRE].ADSGoogle Scholar
  26. [26]
    R. Baier, S.A. Stricker, O. Taanila and A. Vuorinen, Holographic Dilepton Production in a Thermalizing Plasma, JHEP 07 (2012) 094 [arXiv:1205.2998] [INSPIRE].ADSCrossRefGoogle Scholar
  27. [27]
    D. Steineder, S.A. Stricker and A. Vuorinen, Holographic Thermalization at Intermediate Coupling, Phys. Rev. Lett. 110 (2013) 101601 [arXiv:1209.0291] [INSPIRE].ADSCrossRefGoogle Scholar
  28. [28]
    D. Steineder, S.A. Stricker and A. Vuorinen, Probing the pattern of holographic thermalization with photons, JHEP 07 (2013) 014 [arXiv:1304.3404] [INSPIRE].ADSCrossRefGoogle Scholar
  29. [29]
    K.A. Mamo and H.-U. Yee, Gradient Correction to Photon Emission Rate at Strong Coupling, Phys. Rev. D 91 (2015) 086011 [arXiv:1409.7674] [INSPIRE].ADSGoogle Scholar
  30. [30]
    PHENIX collaboration, A. Adare et al., Observation of direct-photon collective flow in \( \sqrt{s_{\;N\;N}}=200 \) GeV Au+Au collisions, Phys. Rev. Lett. 109 (2012) 122302 [arXiv:1105.4126] [INSPIRE].
  31. [31]
    D. Lohner, Measurement of Direct-Photon Elliptic Flow in Pb-Pb Collisions at \( \sqrt{s_{\;N\;N}}=2.76 \) TeV, J. Phys. Conf. Ser. 446 (2013) 012028 [arXiv:1212.3995] [INSPIRE].CrossRefGoogle Scholar
  32. [32]
    B. Müller and D.-L. Yang, Viscous Leptons in the Quark Gluon Plasma, Phys. Rev. D 91 (2015) 125010 [arXiv:1503.06967] [INSPIRE].ADSGoogle Scholar
  33. [33]
    D.-L. Yang and B. Müller, Shear Viscosities of Photons in Strongly Coupled Plasmas, Phys. Lett. B 760 (2016) 565 [arXiv:1507.04232] [INSPIRE].ADSCrossRefGoogle Scholar
  34. [34]
    M. Dion, J.-F. Paquet, B. Schenke, C. Young, S. Jeon and C. Gale, Viscous photons in relativistic heavy ion collisions, Phys. Rev. C 84 (2011) 064901 [arXiv:1109.4405] [INSPIRE].ADSGoogle Scholar
  35. [35]
    C. Shen, U.W. Heinz, J.-F. Paquet, I. Kozlov and C. Gale, Anisotropic flow of thermal photons as a quark-gluon plasma viscometer, Phys. Rev. C 91 (2015) 024908 [arXiv:1308.2111] [INSPIRE].ADSGoogle Scholar
  36. [36]
    A. Bzdak and V. Skokov, Anisotropy of photon production: initial eccentricity or magnetic field, Phys. Rev. Lett. 110 (2013) 192301 [arXiv:1208.5502] [INSPIRE].ADSCrossRefGoogle Scholar
  37. [37]
    K. Fukushima and K. Mameda, Wess-Zumino-Witten action and photons from the Chiral Magnetic Effect, Phys. Rev. D 86 (2012) 071501 [arXiv:1206.3128] [INSPIRE].ADSGoogle Scholar
  38. [38]
    O. Linnyk, W. Cassing and E.L. Bratkovskaya, Centrality dependence of the direct photon yield and elliptic flow in heavy-ion collisions at \( \sqrt{s_{\;N\;N}}=200 \) GeV, Phys. Rev. C 89 (2014) 034908 [arXiv:1311.0279] [INSPIRE].ADSGoogle Scholar
  39. [39]
    L. McLerran and B. Schenke, The Glasma, Photons and the Implications of Anisotropy, Nucl. Phys. A 929 (2014) 71 [arXiv:1403.7462] [INSPIRE].ADSCrossRefGoogle Scholar
  40. [40]
    C. Gale et al., Production and Elliptic Flow of Dileptons and Photons in a Matrix Model of the quark-gluon Plasma, Phys. Rev. Lett. 114 (2015) 072301 [arXiv:1409.4778] [INSPIRE].ADSCrossRefGoogle Scholar
  41. [41]
    A. Monnai, Thermal photon v 2 with slow quark chemical equilibration, Phys. Rev. C 90 (2014) 021901 [arXiv:1403.4225] [INSPIRE].ADSGoogle Scholar
  42. [42]
    O. Linnyk, V. Konchakovski, T. Steinert, W. Cassing and E.L. Bratkovskaya, Hadronic and partonic sources of direct photons in relativistic heavy-ion collisions, Phys. Rev. C 92 (2015) 054914 [arXiv:1504.05699] [INSPIRE].ADSGoogle Scholar
  43. [43]
    L. McLerran and B. Schenke, A Tale of Tails: Photon Rates and Flow in Ultra-Relativistic Heavy Ion Collisions, Nucl. Phys. A 946 (2016) 158 [arXiv:1504.07223] [INSPIRE].ADSCrossRefGoogle Scholar
  44. [44]
    J.-F. Paquet et al., Production of photons in relativistic heavy-ion collisions, Phys. Rev. C 93 (2016) 044906 [arXiv:1509.06738] [INSPIRE].ADSGoogle Scholar
  45. [45]
    V. Vovchenko et al., Electromagnetic probes of a pure-glue initial state in nucleus-nucleus collisions at energies available at the CERN Large Hadron Collider, Phys. Rev. C 94 (2016) 024906 [arXiv:1604.06346] [INSPIRE].ADSGoogle Scholar
  46. [46]
    S.S. Gubser and A. Nellore, Mimicking the QCD equation of state with a dual black hole, Phys. Rev. D 78 (2008) 086007 [arXiv:0804.0434] [INSPIRE].ADSGoogle Scholar
  47. [47]
    S.S. Gubser, A. Nellore, S.S. Pufu and F.D. Rocha, Thermodynamics and bulk viscosity of approximate black hole duals to finite temperature quantum chromodynamics, Phys. Rev. Lett. 101 (2008) 131601 [arXiv:0804.1950] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  48. [48]
    S.I. Finazzo and J. Noronha, Holographic calculation of the electric conductivity of the strongly coupled quark-gluon plasma near the deconfinement transition, Phys. Rev. D 89 (2014) 106008 [arXiv:1311.6675] [INSPIRE].ADSGoogle Scholar
  49. [49]
    M. Greif, I. Bouras, C. Greiner and Z. Xu, Electric conductivity of the quark-gluon plasma investigated using a perturbative QCD based parton cascade, Phys. Rev. D 90 (2014) 094014 [arXiv:1408.7049] [INSPIRE].ADSGoogle Scholar
  50. [50]
    U. Gürsoy and E. Kiritsis, Exploring improved holographic theories for QCD: Part I, JHEP 02 (2008) 032 [arXiv:0707.1324] [INSPIRE].CrossRefGoogle Scholar
  51. [51]
    U. Gürsoy, E. Kiritsis and F. Nitti, Exploring improved holographic theories for QCD: Part II, JHEP 02 (2008) 019 [arXiv:0707.1349] [INSPIRE].CrossRefGoogle Scholar
  52. [52]
    U. Gürsoy, E. Kiritsis, L. Mazzanti and F. Nitti, Deconfinement and Gluon Plasma Dynamics in Improved Holographic QCD, Phys. Rev. Lett. 101 (2008) 181601 [arXiv:0804.0899] [INSPIRE].ADSCrossRefGoogle Scholar
  53. [53]
    U. Gürsoy, E. Kiritsis, L. Mazzanti and F. Nitti, Holography and Thermodynamics of 5D Dilaton-gravity, JHEP 05 (2009) 033 [arXiv:0812.0792] [INSPIRE].MathSciNetCrossRefGoogle Scholar
  54. [54]
    F. Bigazzi, R. Casero, A.L. Cotrone, E. Kiritsis and A. Paredes, Non-critical holography and four-dimensional CFT’s with fundamentals, JHEP 10 (2005) 012 [hep-th/0505140] [INSPIRE].ADSMathSciNetCrossRefGoogle Scholar
  55. [55]
    R. Casero, E. Kiritsis and A. Paredes, Chiral symmetry breaking as open string tachyon condensation, Nucl. Phys. B 787 (2007) 98 [hep-th/0702155] [INSPIRE].ADSCrossRefGoogle Scholar
  56. [56]
    I. Iatrakis, E. Kiritsis and A. Paredes, An AdS/QCD model from tachyon condensation: II, JHEP 11 (2010) 123 [arXiv:1010.1364] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  57. [57]
    I. Iatrakis, E. Kiritsis and A. Paredes, An AdS/QCD model from Sen’s tachyon action, Phys. Rev. D 81 (2010) 115004 [arXiv:1003.2377] [INSPIRE].ADSzbMATHGoogle Scholar
  58. [58]
    M. Jarvinen and E. Kiritsis, Holographic Models for QCD in the Veneziano Limit, JHEP 03 (2012) 002 [arXiv:1112.1261] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  59. [59]
    T. Alho, M. Järvinen, K. Kajantie, E. Kiritsis and K. Tuominen, On finite-temperature holographic QCD in the Veneziano limit, JHEP 01 (2013) 093 [arXiv:1210.4516] [INSPIRE].ADSCrossRefGoogle Scholar
  60. [60]
    D. Arean, I. Iatrakis, M. Järvinen and E. Kiritsis, V-QCD: Spectra, the dilaton and the S-parameter, Phys. Lett. B 720 (2013) 219 [arXiv:1211.6125] [INSPIRE].ADSCrossRefGoogle Scholar
  61. [61]
    D. Areán, I. Iatrakis, M. Järvinen and E. Kiritsis, The discontinuities of conformal transitions and mass spectra of V-QCD, JHEP 11 (2013) 068 [arXiv:1309.2286] [INSPIRE].ADSCrossRefGoogle Scholar
  62. [62]
    D. Arean, I. Iatrakis and M. Järvinen, The spectrum of (h)QCD in the Veneziano limit, PoS(Corfu2012)129 [arXiv:1305.6294] [INSPIRE].
  63. [63]
    T. Alho, M. Järvinen, K. Kajantie, E. Kiritsis, C. Rosen and K. Tuominen, A holographic model for QCD in the Veneziano limit at finite temperature and density, JHEP 04 (2014) 124 [Erratum ibid. 02 (2015) 033] [arXiv:1312.5199] [INSPIRE].
  64. [64]
    I. Iatrakis and I. Zahed, Spectral Functions in V-QCD with Matter: Masses, Susceptibilities, Diffusion and Conductivity, JHEP 04 (2015) 080 [arXiv:1410.8540] [INSPIRE].ADSCrossRefGoogle Scholar
  65. [65]
    T. Alho, M. Jarvinen, K. Kajantie, E. Kiritsis and K. Tuominen, Quantum and stringy corrections to the equation of state of holographic QCD matter and the nature of the chiral transition, Phys. Rev. D 91 (2015) 055017 [arXiv:1501.06379] [INSPIRE].ADSGoogle Scholar
  66. [66]
    M. Jarvinen, Holography and the conformal window in the Veneziano limit, arXiv:1508.00685 [INSPIRE].
  67. [67]
    I. Iatrakis, A. Ramamurti and E. Shuryak, Collective String Interactions in AdS/QCD and High-Multiplicity pA Collisions, Phys. Rev. D 92 (2015) 014011 [arXiv:1503.04759] [INSPIRE].ADSGoogle Scholar
  68. [68]
    E. Kiritsis, Dissecting the string theory dual of QCD, Fortsch. Phys. 57 (2009) 396 [arXiv:0901.1772] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  69. [69]
    U. Gürsoy, E. Kiritsis, L. Mazzanti, G. Michalogiorgakis and F. Nitti, Improved Holographic QCD, Lect. Notes Phys. 828 (2011) 79 [arXiv:1006.5461] [INSPIRE].ADSCrossRefzbMATHGoogle Scholar
  70. [70]
    T. Banks and A. Zaks, On the Phase Structure of Vector-Like Gauge Theories with Massless Fermions, Nucl. Phys. B 196 (1982) 189 [INSPIRE].ADSCrossRefGoogle Scholar
  71. [71]
    A. Sen, Tachyon dynamics in open string theory, Int. J. Mod. Phys. A 20 (2005) 5513 [hep-th/0410103] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  72. [72]
    U. Gürsoy, E. Kiritsis, L. Mazzanti and F. Nitti, Improved Holographic Yang-Mills at Finite Temperature: Comparison with Data, Nucl. Phys. B 820 (2009) 148 [arXiv:0903.2859] [INSPIRE].ADSMathSciNetCrossRefzbMATHGoogle Scholar
  73. [73]
    S.I. Finazzo and R. Rougemont, Thermal photon, dilepton production and electric charge transport in a baryon rich strongly coupled QGP from holography, Phys. Rev. D 93 (2016) 034017 [arXiv:1510.03321] [INSPIRE].ADSGoogle Scholar
  74. [74]
    R. Casero, E. Kiritsis and A. Paredes, Chiral symmetry breaking as open string tachyon condensation, Nucl. Phys. B 787 (2007) 98 [hep-th/0702155] [INSPIRE].ADSCrossRefGoogle Scholar
  75. [75]
    J. Ghiglieri, O. Kaczmarek, M. Laine and F. Meyer, Lattice constraints on the thermal photon rate, Phys. Rev. D 94 (2016) 016005 [arXiv:1604.07544] [INSPIRE].ADSGoogle Scholar
  76. [76]
    B. Hassanain and M. Schvellinger, Diagnostics of plasma photoemission at strong coupling, Phys. Rev. D 85 (2012) 086007 [arXiv:1110.0526] [INSPIRE].ADSzbMATHGoogle Scholar
  77. [77]
    C. Shen, The standard model for relativistic heavy-ion collisions and electromagnetic tomography, Ph.D. Thesis, The Ohio State University (2014) [http://rave.ohiolink.edu/etdc/view?acc_num=osu1405931790] [INSPIRE].
  78. [78]
    C. Shen, Recent developments in the theory of electromagnetic probes in relativistic heavy-ion collisions, arXiv:1511.07708 [INSPIRE].
  79. [79]
    P. Aurenche, M. Fontannaz, J.-P. Guillet, E. Pilon and M. Werlen, A new critical study of photon production in hadronic collisions, Phys. Rev. D 73 (2006) 094007 [hep-ph/0602133] [INSPIRE].
  80. [80]
    J.F. Paquet, Characterizing the non-equilibrium quark-gluon plasma with photons and hadrons, Ph.D. Thesis, McGill University (2015) [http://digitool.Library.McGill.CA:80/R/- ?func=dbin-jump-full&object_id=138949&silo_library=GEN01].
  81. [81]
    K.J. Eskola, H. Paukkunen and C.A. Salgado, EPS09: A New Generation of NLO and LO Nuclear Parton Distribution Functions, JHEP 04 (2009) 065 [arXiv:0902.4154] [INSPIRE].ADSCrossRefGoogle Scholar
  82. [82]
    J.-F. Paquet et al., Production of photons in relativistic heavy-ion collisions, Phys. Rev. C 93 (2016) 044906 [arXiv:1509.06738] [INSPIRE].ADSGoogle Scholar
  83. [83]
    S. Ryu et al., Importance of the Bulk Viscosity of QCD in Ultrarelativistic Heavy-Ion Collisions, Phys. Rev. Lett. 115 (2015) 132301 [arXiv:1502.01675] [INSPIRE].ADSCrossRefGoogle Scholar
  84. [84]
    P. Huovinen and P. Petreczky, QCD Equation of State and Hadron Resonance Gas, Nucl. Phys. A 837 (2010) 26 [arXiv:0912.2541] [INSPIRE].ADSCrossRefGoogle Scholar
  85. [85]
    C. Shen, U. Heinz, P. Huovinen and H. Song, Systematic parameter study of hadron spectra and elliptic flow from viscous hydrodynamic simulations of Au+Au collisions at \( \sqrt{s_{\;N\;N}}=200 \) GeV, Phys. Rev. C 82 (2010) 054904 [arXiv:1010.1856] [INSPIRE].ADSGoogle Scholar
  86. [86]
    S. Turbide, R. Rapp and C. Gale, Hadronic production of thermal photons, Phys. Rev. C 69 (2004) 014903 [hep-ph/0308085] [INSPIRE].
  87. [87]
    R. Rapp and J. Wambach, Chiral symmetry restoration and dileptons in relativistic heavy ion collisions, Adv. Nucl. Phys. 25 (2000) 1 [hep-ph/9909229] [INSPIRE].
  88. [88]
    R. Rapp and C. Gale, Rho properties in a hot gas: Dynamics of meson resonances, Phys. Rev. C 60 (1999) 024903 [hep-ph/9902268] [INSPIRE].
  89. [89]
    W. Liu and R. Rapp, Low-energy thermal photons from meson-meson bremsstrahlung, Nucl. Phys. A 796 (2007) 101 [nucl-th/0604031] [INSPIRE].
  90. [90]
    M. Heffernan, P. Hohler and R. Rapp, Universal Parametrization of Thermal Photon Rates in Hadronic Matter, Phys. Rev. C 91 (2015) 027902 [arXiv:1411.7012] [INSPIRE].ADSGoogle Scholar
  91. [91]
    N.P.M. Holt, P.M. Hohler and R. Rapp, Thermal photon emission from the πρω system, Nucl. Phys. A 945 (2016) 1 [arXiv:1506.09205] [INSPIRE].ADSCrossRefGoogle Scholar
  92. [92]
    C. Shen, U. Heinz, J.-F. Paquet and C. Gale, Thermal photon anisotropic flow serves as a quark-gluon plasma viscometer, arXiv:1403.7558 [INSPIRE].
  93. [93]
    M. Luzum and J.-Y. Ollitrault, Eliminating experimental bias in anisotropic-flow measurements of high-energy nuclear collisions, Phys. Rev. C 87 (2013) 044907 [arXiv:1209.2323] [INSPIRE].ADSGoogle Scholar
  94. [94]
    C. Shen, J.-F. Paquet, J. Liu, G. Denicol, U. Heinz and C. Gale, Event-by-event direct photon anisotropic flow in relativistic heavy-ion collisions, Nucl. Phys. A 931 (2014) 675 [arXiv:1407.8533] [INSPIRE].ADSCrossRefGoogle Scholar
  95. [95]
    PHENIX collaboration, A. Adare et al., Centrality dependence of low-momentum direct-photon production in Au+Au collisions at \( \sqrt{s_{{\;_N}_N}}=200 \) GeV, Phys. Rev. C 91 (2015) 064904 [arXiv:1405.3940] [INSPIRE].
  96. [96]
    ALICE collaboration, Direct photon production in Pb-Pb collisions at \( \sqrt{s_{\;\mathrm{N}\;\mathrm{N}}}=2.76 \) TeV, Phys. Lett. B 754 (2016) 235 [arXiv:1509.07324] [INSPIRE].
  97. [97]
    N.-b. Chang et al., Physics Perspectives of Heavy-Ion Collisions at Very High Energy, Sci. China Phys. Mech. Astron. 59 (2016) 621001 [arXiv:1510.05754] [INSPIRE].CrossRefGoogle Scholar
  98. [98]
    PHENIX collaboration, A. Adare et al., Azimuthally anisotropic emission of low-momentum direct photons in Au+Au collisions at \( \sqrt{s_{\;N\;N}}=200 \) GeV, Phys. Rev. C 94 (2016) 064901 [arXiv:1509.07758] [INSPIRE].
  99. [99]
    D. Lohner, Anisotropic flow of direct photons in Pb-Pb collisions at 2.76 TeV per nucleon, Ph.D. Thesis, Ruperto-Carola-University of Heidelberg, Germany (2013) [doi: 10.11588/heidok.00015650].Google Scholar
  100. [100]
    C. Shen, J.F. Paquet, G.S. Denicol, S. Jeon and C. Gale, Thermal photon radiation in high multiplicity p+Pb collisions at the Large Hadron Collider, Phys. Rev. Lett. 116 (2016) 072301 [arXiv:1504.07989] [INSPIRE].ADSCrossRefGoogle Scholar
  101. [101]
    C. Shen, J.-F. Paquet, G.S. Denicol, S. Jeon and C. Gale, Collectivity and electromagnetic radiation in small systems, Phys. Rev. C 95 (2017) 014906 [arXiv:1609.02590] [INSPIRE].ADSGoogle Scholar
  102. [102]
    S. Benic, K. Fukushima, O. Garcia-Montero and R. Venugopalan, Probing gluon saturation with next-to-leading order photon production at central rapidities in proton-nucleus collisions, JHEP 01 (2017) 115 [arXiv:1609.09424] [INSPIRE].ADSCrossRefGoogle Scholar
  103. [103]
    M. Greif, F. Senzel, H. Kremer, K. Zhou, C. Greiner and Z. Xu, Nonequilibrium photon production in partonic transport simulations, arXiv:1612.05811 [INSPIRE].
  104. [104]
    L. Oliva, M. Ruggieri, S. Plumari, F. Scardina, G.X. Peng and V. Greco, Photons from the Early Stages of Relativistic Heavy Ion Collisions, arXiv:1703.00116 [INSPIRE].
  105. [105]
    J. Berges, K. Reygers, N. Tanji and R. Venugopalan, What shines brighter, Glasma or quark-gluon Plasma: a parametric estimate of photon production at early times in heavy-ion collisions, arXiv:1701.05064 [INSPIRE].
  106. [106]
    S. Turbide, C. Gale, E. Frodermann and U. Heinz, Electromagnetic radiation from nuclear collisions at RHIC energies, Phys. Rev. C 77 (2008) 024909 [arXiv:0712.0732] [INSPIRE].ADSGoogle Scholar
  107. [107]
    P. Romatschke, Retarded correlators in kinetic theory: branch cuts, poles and hydrodynamic onset transitions, Eur. Phys. J. C 76 (2016) 352 [arXiv:1512.02641] [INSPIRE].ADSCrossRefGoogle Scholar

Copyright information

© The Author(s) 2017

Authors and Affiliations

  • Ioannis Iatrakis
    • 1
  • Elias Kiritsis
    • 2
    • 3
    • 4
  • Chun Shen
    • 5
  • Di-Lun Yang
    • 6
    Email author
  1. 1.Institute for Theoretical Physics and Center for Extreme Matter and Emergent PhenomenaUtrecht UniversityUtrechtThe Netherlands
  2. 2.Crete Center for Theoretical Physics, Institute of Theoretical and Computational Physics, Department of PhysicsUniversity of CreteHeraklionGreece
  3. 3.Crete Center for Quantum Complexity and Nanotechnology, Department of PhysicsUniversity of CreteHeraklionGreece
  4. 4.APC, Univ Paris Diderot, Sorbonne Paris Cité, APC, UMR 7164 CNRSParisFrance
  5. 5.Department of PhysicsMcGill UniversityMontrealCanada
  6. 6.Theoretical Research DivisionNishina Center, RIKENWakoJapan

Personalised recommendations