Low energy constituent quark and pion effective couplings to external electromagnetic field and a weak magnetic field

Abstract

In this work, a compilation of effective electromagnetic field couplings to pions and constituent quarks and their effective interactions derived previously, including corrections to the NJL model, is presented. The particular case of a weak external magnetic field along the $\hat{z}$ direction is considered shortly and effective coupling constants are redefined to incorporate the weak-$B_0$ dependence. They correspond to corrections to well known pion-constituent quark couplings and to the NJL and vector NJL effective couplings that break isospin and chiral symmetries.

Comments: 4 pages, work presented by F.L.B, at the XIV International Workshop on Hadron Physics, Florianopolis, Brazil, March 2018