Vector Meson Masses from Hidden Local Symmetry in Constant Magnetic Field

Abstract

We discuss the magnetic responses of vector meson masses based on the hidden local symmetry (HLS) model in constant magnetic field, described by the lightest two-flavor system including the pion, rho and omega mesons in the spectrum. The effective masses influenced under the magnetic field are evaluated in a way of the derivative/chiral expansion established in the HLS model. At the leading order the g-factor of the charged rho meson is fixed to be 2 without any assumptions. Beyond the leading order, one finds anomalous magnetic interactions of the charged rho meson, involving the anomalous magnetic moment, and the sizable corrections to the effective mass. Thus, in contrast to other effective hadron models, the rho meson condensation is unlikely realized in accordance with rigorous arguments on the QCD-theoretical ground, and also current results from the lattice QCD. More remarkably, nontrivial magnetic-dependence of neutral mesons emerges to give rise to the significant mixing among neutral mesons. Consequently, it leads to the dramatic enhancement of the omega meson mass, which is testable in future lattice simulations.