In-medium ω meson mass and quark condensate in a Nambu–Jona-Lasinio model constrained by recent experimental data

Abstract

We have determined the relation between the in-medium $\ensuremath{\omega}$ meson mass and quark condensate in the framework of a Nambu\char21{}Jona-Lasinio model constrained by some recent experimental data on the meson properties in nuclei. In addition to the usual four-quark interactions, we have included eight-quark terms in the Lagrangian. The parameters of this model have been determined using the meson properties in the vacuum as well as in the medium. More particularly, we have constrained both the in-medium pion decay constant to the value measured in experiments on deeply bound pionic atoms and the in-medium $\ensuremath{\omega}$ meson mass to the experimental value obtained either by the TAPS collaboration or by the E325 experiment at KEK Proton Synchrotron. Our results are compared to several scaling laws and in particular to that of G. E. Brown and M. Rho [(Phys. Rep. 398, 301 (2004)].