Charmed Hadrons from Coalescence plus Fragmentation in relativistic nucleus-nucleus collisions at RHIC and LHC

TL;DR

This paper models charmed hadron production in relativistic nucleus-nucleus collisions at RHIC and LHC using coalescence and fragmentation, predicting baryon/meson ratios and spectra across a wide transverse momentum range.

Contribution

It introduces a combined coalescence and fragmentation approach for charmed hadron production, analyzing their ratios and spectra without changing parameters from RHIC to LHC energies.

Findings

The $ m rac{ m ext{Lambda}_c}{D^0}$ ratio reaches 1-1.5 at about 3 GeV/c.

The baryon/meson ratios show weak p_T dependence, similar to light hadron ratios.

Predictions are consistent with other models and thermal expectations.

Abstract

In a coalescence plus fragmentation approach we calculate the heavy baryon/meson ratio and the $p_T$ spectra of charmed hadrons $D^{0}$, $D_{s}$ and $\Lambda_{c}^{+}$ in a wide range of transverse momentum from low $p_T$ up to about 10 GeV and discuss their ratios from RHIC to LHC energies without any change of the coalescence parameters. We have included the contribution from decays of heavy hadron resonances and also the one due to fragmentation of heavy quarks which do not undergo the coalescence process. The coalescence process is tuned to have all charm quarks hadronizing in the $p_T\rightarrow 0$ limit and at finite $p_T$ charm quarks not undergoing coalescence are hadronized by independent fragmentation. The $p_T$ dependence of the baryon/meson ratios are found to be sensitive to the masses of coalescing quarks, in particular the $\Lambda_{c}/D^{0}$ can reach values of about $\rm 1\div 1.5 $ at $p_T \approx \, 3$ \mbox{GeV}, or larger, similarly to the light baryon/meson ratio like $p/\pi$ and $\Lambda/K$, however a marked difference is a quite weak $p_T$ dependence with respect to the light case, such that a larger value at intermediate $p_T$ implies a relatively large value also for the integrated yields. A comparison with other coalescence model and with the prediction of thermal model is discussed.