Measurement of $\Lambda_{\rm c}^{+}$ baryons and ${\rm D}_{\rm s}^{+}$ mesons in Pb-Pb collisions with ALICE

TL;DR

This paper reports on measurements of ${ m D}_{ m s}^{+}$ mesons and $ m \Lambda_c^{+}$ baryons in Pb-Pb collisions at 5.02 TeV to study charm quark behavior and hadronization in the Quark-Gluon Plasma.

Contribution

It provides the latest ALICE measurements of ${ m D}_{ m s}^{+}$ and $ m \Lambda_c^{+}$ production in heavy-ion collisions, offering new insights into charm quark interactions with the QGP.

Findings

Enhanced ${ m D}_{ m s}^{+}$ $R_{AA}$ at low/intermediate $p_T$

Evidence of charm quark thermalization via $v_2$ measurements

Increased $ m \Lambda_c^{+}/D^{0}$ ratio in Pb-Pb collisions

Abstract

The study of heavy-flavour (charm and beauty) production is important to understand the properties of the Quark-Gluon Plasma (QGP) formed in ultra-relativistic heavy-ion collisions, since heavy quarks are produced in the initial stages of the collisions and subsequently interact with the medium throughout its evolution. In the QGP, strange quarks are expected to be abundantly produced and may recombine with charm quarks leading to an enhancement of the nuclear modification factor ($R_{\rm AA}$) of ${\rm D}_{\rm s}^{+}$ mesons compared to that of other charmed meson states at low and intermediate $p_{\rm T}$. The measurement of elliptic flow ($v_{2}$) of ${\rm D}_{\rm s}^{+}$ mesons is useful to determine the degree of thermalisation of charm quarks in the collective expansion of the QGP. In addition, charm quarks could recombine with light di-quark states in the medium, which would lead to an enhancement of the $\Lambda_{\rm c}^{+}/{\rm D}^{0}$ baryon-to-meson ratio as compared to that in pp collisions. Precise measurements of these particle species in Pb-Pb collisions, therefore, give a deeper insight into the hadronisation mechanisms that heavy quarks undergo in the strongly-interacting medium. In this contribution, the latest results measured with ALICE for ${\rm D}_{\rm s}^{+}$-meson and $\Lambda_{\rm c}^{+}$-baryon production in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV, using data from Run 2 of the LHC are discussed.