Geometrical scaling of prompt photons in heavy ion collisions

Abstract

We discuss geometrical scaling (GS) for the prompt (direct) photons produced in heavy ion collisions. To this end we first introduce the concept of GS and illustrate its emergence on the example of charged particles. Next, we analyse direct photon data from RHIC and from the LHC. We show that the data support the hypothesis of GS in terms of participant number related to different centrality classes. We also study GS at different energies, however a more detailed study will be possible only when data for at least three different energies from one experiment will be available and also when we use the data obtained from the collisions of large systems (Cu+Cu, Au+Au, Pb+Pb) and small systems (p+p, d+Au, p+Au).

arXiv comment10 page, 7 figures, talk at the ISMD 2018 in Singapore

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Cited by in corpus (4)

• The color dipole picture for prompt photon production in $pp$ and $pPb$ collisions at the CERN-LHC
• Prompt photon production in high-energy $pA$ collisions at forward rapidity
• Scaling properties of direct photon yields in heavy ion collisions
• Geometrical Scaling of Direct Photons in Relativistic Heavy Ion and d+Au Collisions