Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

A. Adare, Peter Christiansen, Hans-Åke Gustafsson, Eva Haslum, Joakim Nystrand, Anders Oskarsson, Ingvar Otterlund, Sarah Rosendahl, David Silvermyr, Evert Stenlund, Henrik Tydesjö, L. Zou, PHENIX Collaboration

Research output: Contribution to journalArticlepeer-review

Abstract

The PHENIX collaboration presents first measurements of low-momentum (0.41 GeV/c) direct-photon yield dNγdir/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. © 2019 authors. Published by the American Physical Society.
Original languageEnglish
Article number022301
JournalPhysical Review Letters
Volume123
Issue number2
DOIs
Publication statusPublished - 2019 Jul 10

Subject classification (UKÄ)

  • Subatomic Physics

Free keywords

  • Heavy ions
  • Photons
  • Au+Au collisions
  • Collision energies
  • Collision systems
  • Large Hadron Collider
  • Multiplicative factors
  • Relativistic Heavy Ion Collider
  • Scaling behavior
  • Ultrarelativistic heavy ion collision
  • Colliding beam accelerators

Fingerprint

Dive into the research topics of 'Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions'. Together they form a unique fingerprint.

Cite this