Vector meson masses from a hidden local symmetry in a constant magnetic field

Abstract

We discuss the magnetic responses of vector meson masses based on the hidden local symmetry (HLS) model in constant magnetic field, described by the lightest two-flavor system including the pion, rho and omega mesons in the spectrum. The effective masses influenced under the magnetic field are evaluated in a way of the derivative/chiral expansion established in the HLS model. At the leading order O(p 2 ) the g-factor of the charged rho meson is fixed to be 2, implying that the rho meson at this order is treated just like a point-like spin-1 particle. Beyond the leading order, one finds anomalous magnetic interactions of the charged rho meson, involving the anomalous magnetic moment, which give corrections to the effective mass. It is then suggested that up to O(p 4 ) the charged rho meson tends to become massless. Of interest is that nontrivial magnetic-dependence of neutral mesons emerges to give rise to the significant mixing among neutral mesons. Consequently, it leads to the dramatic enhancement of the omega meson mass, which is testable in future lattice simulations. Corrections from terms beyond O(p 4 ) are also addressed.

General structure of the neutral ρ meson self-energy and its spectral properties in a hot and dense magnetized medium

“…The proper time integral in Eqs. (26) and (27) can be performed in order to express the propagators as a sum over discrete Landau levels as…”

Determination of the properties of vector mesons in external magnetic field by quenched SU(3) lattice QCD

“…In order to respect the gauge invariance of the theory on the lattice and satisfy the periodic boundary conditions in space one has to impose the twisted boundary conditions on fermionic fields [36]. In our case they have the following form 12) where N s is the number of lattice sites in spatial directions, q is the quark charge. There is also an additional gauge dependence of the electromagnetic gauge potential and fermion field, which is analogous to the θ-vacuum in QCD [36].…”

“…Then the magnetic field was introduced in two flavor lattice QCD simulation [3] and used as the probe of QCD properties [4]. The energies of hadrons in magnetic fields have been calculated on the lattice [5][6][7][8], in theoretical models [9][10][11][12][13] and in the framework of the QCD sum rules [14,15]. The notion of the hadron polarizability was initially JHEP09(2017)142 discussed in [16,17].…”

Tensor polarizability of the vector mesons from SU(3) lattice gauge theory

“…The magnetic field effect on the hadronic energy and structure was explored by theoretical models [2][3][4][5][6][7][8] as well as lattice calculations [9][10][11][12][13][14][15]. The polarizabilities of hadrons were also investigated by analytical methods using dispersion relations in [16,17], the magnetic moments were studied in [18][19][20][21][22].…”