Modification of the B Meson Mass in a Magnetic Field from QCD Sum Rules

TL;DR

This study uses QCD sum rules to analyze how an external magnetic field affects the mass of the charged B meson, revealing a decrease in mass under different magnetic field strengths.

Contribution

It extends QCD sum rules to estimate B meson mass modifications in magnetic fields, considering both weak and strong field limits, which was not previously explored.

Findings

B meson mass decreases with increasing magnetic field in both limits.

Mass reduction occurs regardless of whether the magnetic field is weak or strong.

The study provides theoretical predictions for meson behavior in magnetic environments.

Abstract

In this paper we extend the well known QCD sum rules used in the calculation of the mass of heavy mesons to estimate the modification of the charged B meson mass, m_B, in the presence of an external Abelian magnetic field, eB. Two simplifying limits were considered: the weak field limit in which the external field satisfies eB << m^2 (with m being any of the masses involved) and the strong field limit in which the field strength is small in comparison to the bottom quark mass (or the B meson mass) squared but it is large compared to the mass of the light quarks, i.e., m^2_{u,d} << eB << m^2_{b,B}. We found that m_B decreases with the magnetic field in the both of these limits.