A1 Journal article (refereed)
Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions (2019)

PHENIX Collaboration. (2019). Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions. Physical Review Letters, 123(2), Article 022301. https://doi.org/10.1103/PhysRevLett.123.022301

JYU authors or editors

Publication details

All authors or editors: PHENIX Collaboration

Journal or series: Physical Review Letters

ISSN: 0031-9007

eISSN: 1079-7114

Publication year: 2019

Volume: 123

Issue number: 2

Article number: 022301

Publisher: American Physical Society

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1103/PhysRevLett.123.022301

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/65158

Publication is parallel published: https://arxiv.org/abs/1805.04084

Abstract

The PHENIX collaboration presents first measurements of low-momentum (0.41  GeV/c) direct-photon yield dNdirγ/dη is a smooth function of dNch/dη and can be well described as proportional to (dNch/dη)α with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high pT (>5  GeV/c), but when results from different collision energies are compared, an additional √sNN-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Keywords: particle physics

Contributing organizations

Ministry reporting: Yes

VIRTA submission year: 2019

JUFO rating: 3