Heavy Quark Recombination Across Collision Systems: Meson and Baryon production
Measurements of heavy-flavor baryons in nucleus--nucleus and proton--proton collisions have provided strong evidence that heavy-quark hadronization cannot be described solely in terms of vacuum fragmentation. In particular, the large enhancement of the $Λ_c/D^0$, $Ξ_c/D^0$ and $Ω_c/D^0$ ratios observed at RHIC and LHC energies has been successfully described within a coalescence plus fragmentation approach, supporting the relevance of recombination mechanisms in both large and small collision systems. Building on these results, we discuss recent developments in the coalescence hadronization framework. Particular emphasis is given to the production of multi-charmed baryons, namely $Ξ_{cc}$, and $Ω_{ccc}$, whose yields are predicted in a wide range of collision systems from PbPb to KrKr, ArAr and OO collisions. The strong sensitivity of these states, especially $Ω_{ccc}$, to the underlying charm-quark distribution makes them valuable probes of charm thermalization and non-equilibrium effects in the QGP. We also present recent extensions of the model to the beauty sector, including predictions for $Λ_b/B^0$, $Ξ_b/B^0$ and $Ω_b/B^0$ production. The results indicate sizeable recombination effects and a stronger baryon enhancement than in the charm sector, highlighting the increasing role of coalescence for heavier quarks. Finally, we briefly comment on ongoing developments toward a unified description of open and hidden heavy flavor through the application of the same framework to quarkonium production in small collision systems.