Ground state energy of a spinor field in the background of a finite radiusflux tube - art. no. 105019

We develop a formalism for the calculation of the ground state energy of a spinor field in the background of a cylindrically symmetric magnetic field. The energy is expressed in terms of the Jost function of the associated sc attering problem. Uniform asymptotic expansions needed are obtained from th e Lippmann-Schwinger equation. The general results derived are applied to t he background of a finite radius flux tube with a homogeneous magnetic fiel d inside and the ground state energy is calculated numerically as a functio n of the radius and the flux. It turns out to be negative, remaining smalle r by a factor of alpha than the classical energy of the background except f or very small values of the radius which are outside the range of applicabi lity of QED. [S0556-2821(99)07118-0].