Static electromagnetic moments and lepton decay constant of the $\rho$-meson in the instant form of relativistic quantum mechanics

TL;DR

This paper presents relativistic calculations of the electromagnetic properties and decay constant of the rho-meson using instant form relativistic quantum mechanics, highlighting the role of Wigner spin rotation.

Contribution

It introduces a modified impulse approximation within the instant form framework to compute rho-meson's electromagnetic form factors and static moments, ensuring Lorentz covariance.

Findings

Nonzero quadrupole moment due to relativistic effects

Consistent electromagnetic form factors with experimental data

Decay constant aligned with observed values

Abstract

The relativistic calculations of the electromagnetic form factors, static moments and lepton decay constant of the $\rho$-meson are given in the framework of the instant form of the relativistic quantum mechanics with different model wave functions. The modified impulse approximation (MIA) is used for the electroweak current operator. MIA provides Lorentz covariance and conservation law for current operators. The developed approach gives the nonzero quadrupole moment due to the relativistic Wigner spin rotation in the $S$-state of the quarks in $\rho$-meson