Radiative hadronization: Photon emission at hadronization from quark-gluon plasma

Abstract

We investigate photon emission at the hadronization stage from a quark-gluon plasma created in relativistic heavy-ion collisions. A recombination-model picture suggests that a quark and an antiquark bind into a meson state in hadronization, which would apparently violate the energy conservation if there is nothing else involved. We consider here a hadronization process where the recombination accompanies a photon emission. This is an analog of the "{\it radiative recombination}" known in plasma physics, such as $e^{-}+p^{+}\to {\mathrm{H}}^0+\gamma$, which occurs when an electromagnetic plasma goes back to a neutral atomic gas. The "radiative hadronization" picture will bring about (i) an enhancement of the photon yield, (ii) significant flow of photons similar to that of hadrons, and (iii) the photon transverse momentum ($p_T$) distribution with a thermal profile whose effective temperature is given by blue-shifted temperature of quarks. Here as a simplest and phenomenological realization of the radiative hadronization, we modify the recombination model to involve a photon emission and evaluate the photon yield with this modified model. Adding this contribution to the direct photon yield along with thermal photon contribution calculated with a hydrodynamic model and a parametrized contribution of prompt photons, we study the $p_T$ spectrum and elliptic flow of the photons produced in heavy-ion collisions at RHIC and LHC energies.

25 pages, 15 figures (Appendix C with Fig.15 is added)

References in corpus (14)

• Viscosity in Strongly Interacting Quantum Field Theories from Black Hole Physics
• The QCD equation of state with dynamical quarks
• Alternative ansatz to wounded nucleon and binary collision scaling in high-energy nuclear collisions
• Coalescence Models For Hadron Formation From Quark Gluon Plasma
• Elliptic flow of identified hadrons in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Quark Coalescence based on a Transport Equation
• Pseudo-Critical Enhancement of Thermal Photons in Relativistic Heavy-Ion Collisions
• Electromagnetic radiation from nuclear collisions at RHIC energies
• Multi-messenger heavy-ion collision physics
• Universal Parametrization of Thermal Photon Rates in Hadronic Matter
• Modeling interactions of photons with pseudoscalar and vector mesons
• Exclusive heavy quarkonium + gamma production from e+ e- annihilation into a virtual photon
• Evidence for $e^{+}{e}^{-}\to \gamma {\chi }_{c1,2}$ at center-of-mass energies from 4.009 to 4.360 GeV
• Evidence for $e^{+}{e}^{-}\to \gamma {\eta }_c(1S)$ at center-of-mass energies between 4.01 and 4.60 GeV

Cited by in corpus (3)

• The Present and Future of QCD
• Bremsstrahlung photon from a hadronizing quark-gluon plasma
• Hydrodynamic model of heavy-ion collisions with low momentum components