Vector meson spectral function and dilepton rate in the presence of strong entanglement effect between the chiral and the Polyakov loop dynamics

Abstract

In this work we have reexplored our earlier study on the vector meson spectral function and its spectral property in the form of dilepton rate in a two-flavor Polyakov loop extended Nambu--Jona-Lasinio (PNJL) model in the presence of a strong entanglement between the chiral and Polyakov loop dynamics. The entanglement considered here is generated through the four-quark scalar-type interaction in which the coupling strength depends on the Polyakov loop and runs with temperature and chemical potential. The entanglement effect is also considered for the four-quark vector-type interaction in the same manner. We observe that the entanglement effect relatively enhances the color degrees of freedom due to the running of both the scalar and vector couplings. This modifies the vector meson spectral function and, thus, the spectral property such as the dilepton production rate in the low invariant mass also gets modified.