Production of muons from heavy flavour decays at forward rapidity in pp and Pb-Pb collisions at $\sqrt {s_{NN}}$ = 2.76 TeV

The ALICE Collaboration has measured the inclusive production of muons from heavy flavour decays at forward rapidity, 2.5 $< y <$ 4, in pp and Pb-Pb collisions at $\sqrt {s_{NN}}$ = 2.76 TeV. The $p_{\rm T}$-differential inclusive cross section of muons from heavy flavour decays in pp collisions is compared to perturbative QCD calculations. The nuclear modification factor is studied as a function of pt and collision centrality. A weak suppression is measured in peripheral collisions. In the most central collisions, a suppression of a factor of about 3-4 is observed in 6 $< p_{\rm T} <$ 10 GeV/$c$. The suppression shows no significant $p_{\rm T}$ dependence.

Figures

Figure 1

Transverse momentum differential inclusive crosssection of muons from heavy flavor decays in $2.5 < y < 4$, in pp collisions at $\sqrt{s}=2.76$ TeV. The verticalerror bars (open boxes) arethe statistical (systematic) uncertainties. The solid curve and the band show FONLL calculations and theoretical uncertainties, respectively. The FONLL calculations are also reported for muons from charm (long dashed curves) and beauty (dot-dashed curves) decays, separately. The lower panel shows the ratio between data and FONLL calculations.
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Figure 2

$\RAA$ of muons from heavy flavor decays in $2.5 < y < 4$ as a function of $\pt$, in the 0-10% (left) and 40-80% (right) centrality classes, in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. Vertical bars (open boxes) represent the statistical (systematic) uncertainty. The filled box centered at $\RAA$= 1 is the normalization uncertainty Horizontal bars show the bin widths.
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Figure 3

$\RAA$ of muons fromheavy flavor decays as a function of the mean number of participating nucleons, in $2.5 < y < 4$ and $ 6 < \pt < 10$ GeV. The horizontal bars indicate the uncertainty on $\langle N_{\rm part} \rangle$.
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