Fractionally charged non-leaking dyons and fermions in a bag

Abstract

We consider a fermion of charge e confined to a spherical bag with a Dirac monopole of strength g at its centre. We find that the boundary conditions making the lowest angular momentum hamiltonian self-adjoint are characterized by a unitary matrix U, and the corresponding vacuum charge has a fractional part 2|eg|α/π where det U=−exp (2iα). Boundary conditions for conservation of helicity, CP, CT and PT are displayed. We demonstrate the possibility of a fractionally charged dyon whose interaction with a fermion conserves helicity. We also show that the simultaneous validity of helicity, CP, CT and PT requires integer vacuum charge.