In-medium hadronization of heavy quarks and its effect on charmed meson and baryon distributions in heavy-ion collisions

TL;DR

This paper introduces a new model for heavy-quark hadronization in heavy-ion collisions, emphasizing local recombination with thermal light quarks and diquarks, which impacts charmed hadron yields and flow patterns.

Contribution

The model incorporates local color neutralization and recombination with diquarks, providing a novel explanation for charmed baryon enhancement and flow in heavy-ion collisions.

Findings

Enhanced charmed baryon yields due to diquark recombination

Strong space-momentum correlations increase charmed hadron flow

Low-mass clusters decay isotropically, affecting momentum distributions

Abstract

We present a new model for the description of heavy-quark hadronization in relativistic heavy-ion collisions in the presence of a reservoir of lighter thermal particles with which recombination can occur leading to the formation of color-singlet clusters. Color neutralization is assumed to occur locally, within the same fluid cell occupied by the heavy quark and it proceeds via the recombination of the latter with light antiquarks (quarks) or diquarks (anti-diquarks), which are assumed to be present in the medium with thermal abundance as effective degrees of freedom around the QCD crossover temperature $T_c$. Typically the resulting color-singlet clusters have quite low invariant mass, in most of the cases below 4 GeV, and in this case they are assumed to undergo an isotropic 2-body decay in their local rest-frame. Heavier clusters are instead fragmented as Lund strings. The possibility of recombination with light diquarks enhances the yields of charmed baryons, in qualitative agreement with recent measurements. The assumption of local color neutralization leads to a strong space-momentum correlation, which provides a substantial enhancement of the collective flow of the final-state charmed hadrons, affecting both their momentum and their angular distributions