Nucleon and Δ isobar in a strong magnetic field

Abstract

We investigate the static properties of the nucleon in the presence of strong magnetic fields and discuss the consequent changes of the nucleon structure, based on the Skyrme model. The results show that at large values of the magnetic field (∼ 10 17 to 10 18 G), which is supposed to appear in heavy-ion collision experiments at RHIC energies, the soliton starts to deviate from the spherically symmetric form and its size starts to change. At extremely large values of the magnetic field (∼ 10 19 G), which may be found at the LHC experiments, the soliton becomes more compact than in free space. The results also show that in the presence of the external magnetic field, the mass of the nucleon tends to increase in general and the mass degeneracy of the ∆ isobars from isospin symmetry will be lifted. We also discuss the changes in the mass difference between the ∆ and the nucleon, ∆m∆N, due to the influence of the external magnetic field. We find that ∆m∆N increases as the strength of the magnetic field grows.

Deuteron under strong magnetic fields: Skyrme model study*

“…Considering the axial symmetry imposed by magnetic fields, we follow the ansatz in Ref. [8] to deform the spatial space as…”

“…Many theoretical investigations based on the lattice QCD method or effective QCD theories, such as NJL models, have shown that strong magnetic fields can modify the quark potential and meson properties owing to complex QED-QCD interactions [5][6][7]. However, there are relatively few studies in regard to the modification of baryon properties in the presence of strong magnetic fields [8][9][10].…”

“…In this study, we modify the method proposed by Ref. [8] to study the deuteron as a skyrmion. Besides the conventional Skyrme model (labeled as the SKM), the effects of the derivative dependent sextic Lagrangian term are also considered (labeled as the gSKM).…”

“…Note that the quantization method in Ref. [8] consists of allowing the valued field in the Skyrme model to rotate in threedimensional isospin space and spatial space only in the x -y plane, which is inconsistent with the constraint of Eq. ( 21) resulting from the cylindrical symmetry implicitly imposed on the solution of the skyrmion in this study when we quantize the skyrmion.…”

The pole and screening masses of neutral pion in hot and magnetized medium: a comprehensive study in the Nambu--Jona-Lasinio model

“…For another, since neutral pions are Nambu-Goldstone bosons of the chiral symmetry breaking, the modifications of their properties in an external magnetic field will help to understand the effects of magnetic fields on the chiral phase transition, and thus are extensively investigated recently . Furthermore, there are some other works involving heavy mesons [60][61][62][63][64][65][66][67][68][69][70][71] and baryons [72][73][74][75][76][77][78] in the magnetic field.…”