Measurement of the production of high-$p_{\mathrm{T}}$ electrons from heavy-flavour hadron decays in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV

Abstract

Electrons from heavy-flavour hadron decays (charm and beauty) were measured with the ALICE detector in Pb-Pb collisions at a centre-of-mass of energy $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV. The transverse momentum ($p_{\mathrm{T}}$) differential production yields at mid-rapidity were used to calculate the nuclear modification factor $R_{\mathrm{AA}}$ in the interval $3<p_{\mathrm{T}}<18$ GeV/$c$. The $R_{\mathrm{AA}}$ shows a strong suppression compared to binary scaling of pp collisions at the same energy (up to a factor of 4) in the 10% most central Pb-Pb collisions. There is a centrality trend of suppression, and a weaker suppression (down to a factor of 2) in semi-peripheral (50-80%) collisions is observed. The suppression of electrons in this broad $p_{\mathrm{T}}$ interval indicates that both charm and beauty quarks lose energy when they traverse the hot medium formed in Pb-Pb collisions at LHC.

28 pages, 7 captioned figures, 2 tables, authors from page 23, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/3162