A dimension five Lorentz-violating nonminimal coupling for mesons in the KLZ model

TL;DR

This paper explores a Lorentz-violating nonminimal coupling in the KLZ model, analyzing its effects on meson interactions, pion form factors, and decay rates, and deriving experimental bounds on the LV parameters.

Contribution

It introduces a dimension five Lorentz-violating coupling into the KLZ model and studies its impact on meson phenomenology and experimental constraints.

Findings

LV coupling induces linear momentum dependence in pion form factor

Upper bounds on LV parameters from muon magnetic moment data

Recalculated rho decay rate constrains LV parameter magnitude

Abstract

We investigate a dimension five Lorentz-violating (LV) nonminimal coupling between the neutral vector meson field strength and the pion current in the context of the Kroll-Lee-Zumino (KLZ) model. In this modified model we study the vector meson dominance (VMD) through of the imposing of new universality conditions between the couplings that comes from LV contributions. We also show that the LV nonminimal coupling leads to a linear momentum dependence in the timelike pion form factor, that is used to evaluate LV corrections for the muon anomalous magnetic moment. The experimental imprecision of such quantity allows us to obtain upper bound $\bar{g}\xi_{0} < 1.0 \mathbf{~}\mathrm{{GeV}}^{-1}.$ In addition, we also use the LV nonminimal coupling in the KLZ model to recalculate the $\rho$ decay rate. In this case the experimental imprecision is used to constrain the magnitude of the LV parameter at the level of $\bar{g}\xi_{0} < 1.9\times10^{-2}\mathbf{~}\mathrm{{GeV}}^{-1}$.