We study the quantum rotating soliton in the nonlinear σ model which is obtained by minimizing the total energies of rotating soliton. Existence of such a soliton is expected from the Derrick’s theorem even when the Skyrme term is absent because the rotational energy prevents the soliton from collapsing. The asymptotic behavior of the profile function is shown to be determined by the physical pion mass which appears in the PCAC relation in the nonlinear σ model. The energies of spin-1/2 and − 3/2 solitons are obtained numerically with the use of a simple trial function.
Proton decay matrix element on lattice at physical pion mass