D mesons at finite temperature and density in the PNJL model

TL;DR

This paper investigates D meson properties in hot, dense quark matter using the PNJL model, revealing moderate mass splitting and significant spectral broadening at high densities, impacting J/psi dissociation understanding.

Contribution

It provides new insights into D meson mass behavior and decay widths in hot, dense environments, challenging previous hadronic models and emphasizing spectral broadening effects.

Findings

Mass splitting between D^+ and D^- is moderate, not exceeding 100 MeV.

Decay width reaches about 200 MeV at high densities, indicating spectral broadening.

D meson masses do not significantly drop in the medium, contrary to some models.

Abstract

We study D meson resonances in hot, dense quark matter within the NJL model and its Polyakov-loop extension. We show that the mass splitting between D^+ and D^- mesons is moderate, not in excess of 100 MeV. When the decay channel into quasifree quarks opens (Mott effect) at densities above twice saturation density, the decay width reaches rapidly the value of 200 MeV which entails a spectral broadening sufficient to open J/psi dissociation processes. Contrary to results from hadronic mean-field theories, the chiral quark model does not support the scenario of a dropping D meson masses so that scenarios for J/psi dissociation by quark rearrangement built on the lowering of the threshold for this process in a hot and dense medium have to be reconsidered and should account for the spectral broadening.