Charmonium production in hot magnetized hyperonic matter -- effects of baryonic Dirac sea and pseudoscalar-vector meson mixing

Abstract

We investigate the medium modifications of the masses of pseudoscalar open charm ($D$ and $\bar D$) mesons and the charmonium state ($\psi(3770)$) in hot isospin asymmetric strange hadronic medium in the presence of an external magnetic field within a chiral effective model. The in-medium partial decay widths of $\psi(3770)$ to $D\bar D$ mesons are computed from the in-medium masses of the initial and final state mesons. These are computed using two light quark pair creation models - (I) the $^3P_0$ model and (II) a field theoretical (FT) model of composite hadrons with quark (and antiquark) constituents. The production cross-sections of $\psi(3770)$, arising from scattering of the $D$ and $\bar D$ mesons, are computed from the relativistic Breit-Wigner spectral function expressed in terms of the in-medium masses and the decay widths of the charmonium state. The effects of the magnetic field are considered due to the Dirac sea (DS) of the baryons, the mixing of the pseudoscalar and vector meson (PV mixing) and the Landau level contributions for the charged hadrons. The production cross-sections of $\psi(3770)$ arising due to scattering of $D^+D^-(D^0\bar{D}^0)$ mesons in the hot magnetized strange hadronic matter are observed to have distinct peak positions, when the magnetic field is large, due to the mass difference of the transverse and longitudinal components of $\psi(3770)$, arising from PV mixing. These can have observable consequences on the dilepton spectra and the production of the charm mesons in ultra-relativistic peripheral heavy ion collision experiments, where the produced magnetic field is huge.