The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

David Silvermyr

David Silvermyr

Senior lecturer

David Silvermyr

Low-momentum direct-photon measurement in Cu + Cu collisions at sNN =200 GeV

Author

  • A. Adare
  • Hans-Åke Gustafsson
  • Eva Haslum
  • Anders Oskarsson
  • Sarah Rosendahl
  • David Silvermyr
  • Evert Stenlund
  • L. Zou

Summary, in English

We measured direct photons for pT<5GeV/c in minimum bias and 0%–40% most-central events at midrapidity for Cu+Cu collisions at √sNN=200GeV. The e+e− contribution from quasireal direct virtual photons has been determined as an excess over the known hadronic contributions in the e+e− mass distribution. A clear enhancement of photons over the binary scaled p+p fit is observed for pT<4GeV/c in Cu+Cu data. The pT spectra are consistent with the Au+Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the p+p baseline are 285±53(stat)±57(syst)MeV/c and 333±72(stat)±45(syst)MeV/c for minimum bias and 0%–40% most-central events, respectively. The rapidity density, dN/dy, of photons demonstrates the same power law as a function of dNch/dη observed in Au+Au at the same collision energy.

Department/s

  • Particle and nuclear physics

Publishing year

2018

Language

English

Publication/Series

Physical Review C

Volume

98

Issue

5

Document type

Journal article

Publisher

American Physical Society

Topic

  • Subatomic Physics

Status

Published

ISBN/ISSN/Other

  • ISSN: 2469-9985