Direct photon elliptic flow in Pb-Pb collisions at root s(NN)=2.76 TeV

The ALICE Collaboration, S. Acharya, E. J. Brücken, B. Chang, T. E. Hilden, D. J. Kim, V. Litichevskyi, M. M. Mieskolainen, R. Orava, J. E. Parkkila, J. Rak, S. S. Räsänen, S. Saarinen, M. Slupecki, T. W. Snellman, W. H. Trzaska, M. Vargyas, J. Viinikainen

Research output: Contribution to journalArticleScientificpeer-review

Abstract

The elliptic flow of inclusive and direct photons was measured at mid-rapidity in two centrality classes 0-20% and 20-40% in Pb-Pb collisions at root s(NN) = 2.76 TeV by ALICE. Photons were detected with the highly segmented electromagnetic calorimeter PHOS and via conversions in the detector material with the e(broken vertical bar)e pairs reconstructed in the central tracking system. The results of the two methods were combined and the direct-photon elliptic flow was extracted in the transverse momentum range 0.9 < p(T) < 6.2 GeV/c. A comparison to RHIC data shows a similar magnitude of the measured direct-photon elliptic flow. Hydrodynamic and transport model calculations are systematically lower than the data, but are found to be compatible. (C) 2018 The Author. Published by Elsevier B.V.
Original languageEnglish
JournalPhysics Letters B
Volume789
Pages (from-to)308-322
Number of pages15
ISSN0370-2693
DOIs
Publication statusPublished - 10 Feb 2019
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 114 Physical sciences
  • QUARK-GLUON PLASMA
  • TRANSVERSE-MOMENTUM
  • NEUTRAL PION
  • PERSPECTIVE
  • DEPENDENCE

Cite this

The ALICE Collaboration, Acharya, S., Brücken, E. J., Chang, B., Hilden, T. E., Kim, D. J., Litichevskyi, V., Mieskolainen, M. M., Orava, R., Parkkila, J. E., Rak, J., Räsänen, S. S., Saarinen, S., Slupecki, M., Snellman, T. W., Trzaska, W. H., Vargyas, M., & Viinikainen, J. (2019). Direct photon elliptic flow in Pb-Pb collisions at root s(NN)=2.76 TeV. Physics Letters B, 789, 308-322. https://doi.org/10.1016/j.physletb.2018.11.039