The properties of D and D* mesons in the nuclear medium

TL;DR

This paper investigates the in-medium properties of D and D* mesons in nuclear matter using a self-consistent coupled-channel approach that respects heavy-quark symmetry, analyzing spectral functions, resonances, and potentials across different densities.

Contribution

It introduces a self-consistent method incorporating heavy-quark symmetry and advanced renormalization to study D and D* mesons in nuclear matter, improving upon previous models.

Findings

D meson potential remains attractive at higher densities.

D* meson potential is repulsive and broadens with density.

Spectral functions reveal resonance-hole mode interactions and density effects.

Abstract

We study the properties of $D$ and $D^*$ mesons in nuclear matter within a simultaneous self-consistent coupled-channel unitary approach that implements heavy-quark symmetry. The in-medium solution accounts for Pauli blocking effects, and for the $D$ and $D^*$ self-energies in a self-consistent manner. We pay a special attention to the renormalization of the intermediate propagators in the medium beyond the usual cutoff scheme. We analyze the behavior in the nuclear medium of the rich spectrum of dynamically-generated baryonic resonances in the C=1 and S=0 sector, and their influence in the self-energy and, hence, the spectral function of the $D$ and $D^*$ mesons. The $D$ meson quasiparticle peak mixes with $\Sigma_c(2823)N^{-1}$ and $\Sigma_c(2868)N^{-1}$ states while the $\Lambda_c(2595)N^{-1}$ mode is present in the low-energy tail of the spectral function. The $D^*$ spectral function incorporates $J=3/2$ resonances, and $\Sigma_c(2902)N^{-1}$ and $\Lambda_c(2941)N^{-1}$ fully determine the behavior of $D^*$ meson spectral function at the quasiparticle peak. As density increases, these resonant-hole modes tend to smear out and the spectral functions get broad. We also obtain the $D$ and $D^*$ scattering lengths, and optical potentials for different density regimes. The $D$ meson potential stays attractive while the $D^*$ meson one is repulsive with increasing densities up to twice that of the normal nuclear matter. Compared to previous in-medium SU(4) models, we obtain similar values for the real part of the $D$ meson potential but much smaller imaginary parts. This result can have important implications for the observation of $D^0$-nucleus bound states.