Modification of the B meson mass in a magnetic field from QCD sum rules

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Processo FAPESP: 11/05619-3

Processo FAPESP: 12/21627-9

Processo FAPESP: 11/21691-6

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(u,d)(2) << eB << m(b,B)(2). We found that m(B) decreases with the magnetic field in both of these limits.