PoS - Proceedings of Science
Volume 449 - The European Physical Society Conference on High Energy Physics (EPS-HEP2023) - T05 Ultra-Relativistic Nuclear Collisions
Electromagnetic radiation in pp and Pb--Pb collisions with dielectrons in ALICE
H.ย MuraKami* ย on behalf of the ALICE collaboration
Full text: pdf
Pre-published on: December 18, 2023
Published on: March 21, 2024
Abstract
The latest ALICE results on low $๐‘_{{\rm T}}$ direct photon measurements via the virtual photon method are presented. Direct photons are measured in Pbโ€“Pb collisions at $\sqrt{s}_{{\rm NN}}$ = 5.02 TeV, and in minimum-bias (MB) and high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV with LHC Run 2 data. The virtual direct-photon signal is extracted from the dielectron mass spectra. Direct photon spectrum in Pbโ€“Pb collisions is measured in the range 1 < $๐‘_{{\rm T}}$ < 5 GeV/$๐‘$ and compared with theoretical predictions. In pp collisions, such measurement in minimum-bias events serves as a baseline for Pbโ€“Pb collisions and a fundamental test for perturbative QCD (pQCD) calculations, while studies in high charged-particle multiplicity events allow one to search for thermal radiation in small colliding systems. Direct photon spectra in pp collisions for both event multiplicity classes are measured in the range 1 < $๐‘_{{\rm T}}$ < 6 GeV/$๐‘$. The MB result was compared with NLO pQCD calculations and the viscous hydrodynamical model. Finally, the first result with the Run 3 pp data at $\sqrt{s}$ = 13.6 TeV, using the upgraded ALICE detector to disentangle the different dielectron sources, is reported.
DOI: https://doi.org/10.22323/1.449.0207
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
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.