Measurement of electrons from beauty-hadron decays in p-Pb collisions at sNN=5.02 \sqrt{s_{\mathrm{NN}}}=5.02 TeV and Pb-Pb collisions at sNN=2.76 \sqrt{s_{\mathrm{NN}}}=2.76 TeV

Collaboration
Sep 13, 2016
34 pages
Published in:
  • JHEP 07 (2017) 052
  • Published: Jul 11, 2017
e-Print:
Report number:
  • CERN-EP-2016-222
Experiments:

Citations per year

2016201820202022202402468101214
Abstract: (Springer)
The production of beauty hadrons was measured via semi-leptonic decays at mid-rapidity with the ALICE detector at the LHC in the transverse momentum interval 1T_{T} < 8 GeV/c in minimum-bias p-Pb collisions at sNN=5.02 \sqrt{s_{\mathrm{NN}}}=5.02 TeV and in 1.3 < pT_{T} < 8 GeV/c in the 20% most central Pb-Pb collisions at sNN=2.76 \sqrt{s_{\mathrm{NN}}}=2.76 TeV. The pp reference spectra at sNN=5.02 \sqrt{s_{\mathrm{NN}}}=5.02 TeV and s=2.76 \sqrt{s}=2.76 TeV, needed for the calculation of the nuclear modification factors RpPb_{pPb} and RPbPb_{PbPb}, were obtained by a pQCD-driven scaling of the cross section of electrons from beauty-hadron decays measured at s=7 \sqrt{s}=7 TeV. In the pT_{T} interval 3 < pT_{T} < 8 GeV/c, a suppression of the yield of electrons from beauty-hadron decays is observed in Pb-Pb compared to pp collisions. Towards lower pT_{T}, the RPbPb_{PbPb} values increase with large systematic uncertainties. The RpPb_{pPb} is consistent with unity within systematic uncertainties and is well described by theoretical calculations that include cold nuclear matter effects in p-Pb collisions. The measured RpPb_{pPb} and these calculations indicate that cold nuclear matter effects are small at high transverse momentum also in Pb-Pb collisions. Therefore, the observed reduction of RPbPb_{PbPb} below unity at high pT_{T} may be ascribed to an effect of the hot and dense medium formed in Pb-Pb collisions.
Note:
  • Heavy Ion Experiments
  • electron
  • bottom: decay
  • hadron: decay
  • semileptonic decay
  • nuclear matter: effect
  • transverse momentum: high
  • cross section: scaling
  • rapidity
  • Bjorken