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 1 < PT < 8 GeV/c in minimum-bias p-Pb collisions at root(NN)-N-S = 5.02 TeV and in 1.3 < PT < 8 GeV/c in the 20% most central Pb-Pb collisions at root(NN)-N-S = 2.76 TeV. The pp reference spectra at root s = 5.02 TeV and root s = 2.76 TeV, needed for the calculation of the nuclear modification factors RpPb and R-PbPb, were obtained by a pQCD-driven scaling of the cross section of electrons from beauty-hadron decays measured at root s = 7 TeV. In the PT interval 3 < PT < 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, the R-PbPb values increase with large systematic uncertainties. The R-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 R-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 R-PbPb below unity at high PT may be ascribed to an effect of the hot and dense medium formed in Pb-Pb collisions.
Measurement of electrons from beauty-hadron decays in p-Pb collisions at sNN=5.02 TeV and Pb-Pb collisions at sNN=2.76 TeV / Adam, J.; Adamova, D.; Aggarwal, M.; Rinella, G.; Agnello, M.; Agrawal, N; Bufalino, S.; Ravasenga, I.; Ahammed, Z.; Ahn, S. U.; Aiola, S.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1126-6708. - STAMPA. - 2017:7(2017), pp. 0-39. [10.1007/JHEP07(2017)052]
|Titolo:||Measurement of electrons from beauty-hadron decays in p-Pb collisions at sNN=5.02 TeV and Pb-Pb collisions at sNN=2.76 TeV|
|Data di pubblicazione:||2017|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/JHEP07(2017)052|
|Appare nelle tipologie:||1.1 Articolo in rivista|
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