Volume 345 - International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (HardProbes2018) - Electroweak Probes
PHENIX Measurements of Beam EnergyDependence of Direct Photon Emission
A. Drees* On behalf of the PHENIX collaboration
*corresponding author
Full text: pdf
Pre-published on: January 21, 2019
Published on: April 24, 2019
Abstract
In this talk the PHENIX collaboration presents new measurements of low momentum direct photons from Cu+Cu at 200 GeV and Au+Au at 62.4 GeV and 39 GeV. A large excess of direct photons over the scaled $p$+$p$ yield is found. The comparison of the new data with data from Au+Au at 200 GeV and ALICE data from 2.76 TeV reveals that at low-$p_{T}$ the spectra of direct photons and their integrated yield above 1 GeV/c follow a universal scaling as a function of the charged-particle multiplicity, $(dN_{ch}/d\eta)^{\alpha}$, with $\alpha = 1.25$, independent of collision centrality or center of mass energy. The observed scaling properties suggests that the emission source has similar properties for all observed systems.
DOI: https://doi.org/10.22323/1.345.0176
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access