Magnetic moment of the rho meson in instant-form relativistic quantum mechanics

TL;DR

This paper presents an analytical calculation of the rho meson's magnetic dipole moment using a relativistic constituent-quark model, achieving results consistent with experimental data and recent lattice QCD findings.

Contribution

The paper introduces a parameter-free relativistic approach within instant-form RQM to compute meson magnetic moments, extending previous models to include detailed form factors.

Findings

Calculated mu_rho = (2.16 ± 0.03) e/2M_rho in agreement with experimental data.

Derived magnetic, quadrupole, and charge form factors for the rho meson.

Compared results with lattice QCD and prior theoretical calculations.

Abstract

We derive an explicit analytical expression for the magnetic dipole moment of the rho meson, mu_rho, in a relativistic constituent-quark model. We adopt our relativistic approach to composite systems, modified instant-form (mIF) Relativistic Quantum Mechanics (RQM), that we used particularly to construct a unified pi&rho model (Phys. Rev. D93, 036007 (2016) = arXiv:1602.00907) describing electroweak properties of light mesons. This model provides a parameter-free calculation to give mu_rho=(2.16+-0.03) [e/2M_rho] which is in accordance with the conventional experimental data. The magnetic, quadrupole and charge form factors also are derived and presented. We consider the small uncertainty of our value of magnetic moment as one of undoubted advantages of the method. A comparison is made with recent lattice QCD results and previous calculations using a variety of methods.