Vector Coupling and Rho Meson in a Nonlocal Nambu-Jona-Lasinio Model

Abstract

A vector coupling term apart from the scalar and psendoscalar terms, is introduced into the nonlocal quark-(anti-)quark interaction in an extended Nambu-Jona-Lasinio model to investigate the vector rho meson mode in the relativistic random phase approximation (RPA). It is shown that a favorabJe choice of the vector coupling to fit the empirical data has to be the same form as that of the original scalar and pseudoscalar ones but with a necessary negative sign.

An Improvement on RPA Based on a Boson Description

“…In nuclear physics it is widely employed to define surface oscillation and pair oscillation [1]. Recently the RPA has also been used to study mesons in terms of the quark-antiquark degrees of freedom [2,3].…”