Photons from the Early Stages of Relativistic Heavy Ion Collisions
| Autor: | Lucia Oliva, Guang-Xiong Peng, Marco Ruggieri, Salvatore Plumari, Francesco Scardina, Vincenzo Greco |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Nuclear and High Energy Physics
Particle physics Photon Nuclear Theory Nuclear Theory Nuclear Theory High Energy Physics - Experiment High Energy Physics - Phenomenology Nuclear Experiment Nuclear and High Energy Physics FOS: Physical sciences Kinetic energy 01 natural sciences High Energy Physics - Experiment Nuclear Theory (nucl-th) Nuclear physics High Energy Physics - Experiment (hep-ex) High Energy Physics - Phenomenology (hep-ph) 0103 physical sciences Nuclear Experiment (nucl-ex) 010306 general physics Nuclear Experiment Physics 010308 nuclear & particles physics High Energy Physics::Phenomenology Plasma Collision Coupling (probability) Gluon High Energy Physics - Phenomenology Quark–gluon plasma High Energy Physics::Experiment Energy (signal processing) |
| Popis: | We present results about photons production in relativistic heavy ion collisions. The main novelty of our study is the calculation of the contribution of the early stage photons to the photon spectrum. The initial stage is modeled by an ensemble of classical gluon fields which decay to a quark-gluon plasma via the Schwinger mechanism, and the evolution of the system is studied by coupling classical field equations to relativistic kinetic theory; photons production is then computed by including the pertinent collision processes into the collision integral. We find that the contribution of the early stage photons to the direct photon spectrum is substantial for $p_T \approx 2$ GeV and higher, the exact value depending on the collision energy; therefore we identify this part of the photon spectrum as the sign of the early stage. Moreover, the amount of photons produced during the early stage is not negligible with respect to those produced by a thermalized quark-gluon plasma: we support the idea that there is no dark age in relativistic heavy ion collisions. 11 pages, 9 figures. Matches published version |
| Databáze: | OpenAIRE |
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