Study of charm hadronization with prompt $\Lambda_c^+$ baryons in proton-proton and lead-lead collisions at $\sqrt{s_\mathrm{NN}}= 5.02~\mathrm{TeV}$

The production of prompt $\Lambda_c^+$ baryons is measured via the exclusive decay channel $\Lambda_c^+ \to \mathrm{p} \mathrm{K}^- \pi^+$ at a center-of-mass energy per nucleon pair of $5.02~\mathrm{TeV}$ using $252~\mathrm{nb}^{-1}$ proton-proton (pp) and $0.607~\mathrm{nb}^{-1}$ lead-lead (PbPb) collisions collected at the CERN LHC in 2017 and 2018, respectively. The measurements are performed within the $\Lambda_c^+$ rapidity interval $|y|<1.0$ with transverse momentum ($p_\mathrm{T}$) ranges of 3--30 and 6--40 $\mathrm{GeV}/c$ for pp and PbPb collisions, respectively. Compared to pp collisions scaled by the number of nucleon-nucleon interactions, the observed yields of $\Lambda_c^+$ with $p_\mathrm{T}>10~\mathrm{GeV}/c$ are strongly suppressed in PbPb collisions. The level of suppression depends significantly on both the collision centrality and the $p_\mathrm{T}$ of the $\Lambda_c^+$ baryon. The $\Lambda_c^+/\mathrm{D}^0$ production ratio in PbPb collisions is consistent with the result in pp collisions for $p_\mathrm{T}>10~\mathrm{GeV}/c$, suggesting that the coalescence process of hadronization is not significant for PbPb collisions in the higher $p_\mathrm{T}$ region.