Measurements of the heavy-flavour nuclear modification factor in p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with ALICE at the LHC

TL;DR

This paper reports measurements of the heavy-flavour nuclear modification factor in p--Pb collisions at 5.02 TeV, showing mostly no suppression and providing insights into initial-state effects and medium interactions in heavy-ion collisions.

Contribution

First measurement of $R_{pPb}$ for heavy-flavour in p--Pb at 5.02 TeV across wide kinematic ranges with multiple decay channels.

Findings

$R_{pPb}$ is consistent with unity at mid and forward rapidity.

Slight enhancement of heavy-flavour decay muons in backward region for $2<p_T<4$ GeV/c.

Results align with theoretical models including initial-state effects.

Abstract

The heavy-flavour nuclear modification factor $R_{\rm pPb}$ has been measured with the ALICE detector in p--Pb collisions at the nucleon--nucleon center of mass energy $\sqrt{s_{\rm NN}}$ = 5.02 TeV at the CERN LHC in a wide rapidity and transverse momentum range, as well as in several decay channels. $R_{\rm pPb}$ is consistent with unity within uncertainties at mid-rapidity and forward rapidity. In the backward region a slight enhancement of the yield of heavy-flavour decay muons is found in the region $2<p_{\rm T}<4$ GeV/$c$. The results are described within uncertainties by theoretical calculations that include initial-state effects. The measurements add experimental evidence that the suppression of heavy-flavour production observed at high $p_{\rm T}$ in central Pb--Pb collisions with respect to pp collisions is due to a medium effect induced by the interaction of heavy quarks with the partonic matter.