Magnetic field induced anomalous pion couplings

Abstract

Effective pion-constituent quark couplings induced by relatively weak magnetic fields are calculated in the framework based in Weinberg's large Nc Effective Field Theory. These couplings (form factors) vanish in the vacuum. In particular, single-pion couplings to a scalar and a vector constituent quark currents are investigated. These couplings might correspond to a fluctuation of the neutral pion into a scalar quark-antiquark state (meson) and to a vector meson, respectively. Some possible phenomenological implications are discussed.

Comments: 9 pages, 10 figures, revised manuscript