Skyrmions coupled to the electromagnetic field via the gauged Wess-Zumino term

Abstract

In soliton models expressed in terms of the nonlinear chiral field, the electric current has an anomalous gauge-field contribution as the baryon current does. We study the spin polarized Skyrmions coupled with the electromagnetic field via the gauged Wess-Zumino term and calculate configurations of the Skyrmion and the gauge field with boundary conditions to ensure the physical charge number for baryons. Although the electromagnetic field via the gauged Wess-Zumino term affects physical quantities in small amounts, we find that the magnetic field forms a dipole structure owing to a circular electric current around the spin-quantization axis of the soliton. This is understood on an analogy with the Meissner effect in the super conductor. The electric-charge distributions turn out to have characteristic structures depending on the total charge, which suggests the intrinsic deformation of baryons due to orbital motions of the constituents.

Magnetic enhancement of baryon confinement modeled via a deformed Skyrmion

“…[28], and this discrepancy is explainable from our approximation of full polarization (see also, e.g., Ref. [29] in which a similar approximation was adopted). Conclusively, by such an effective nucleon magnetic moment µ p,n we yield the nucleon pressure from the sum rule, P p,n = −(2/3)µ p,n • B.…”