Mass Shift of Axion in Magnetic Field

Abstract

A mass-shift of the axion propagating in an external constant homogenious magnetic field is calculated. The contributions via an electron loop and a virtual photon are examined. It is shown that the virtual photon contribution dominates substantially over the electron-loop one. Under the conditions of the early Universe the electron-loop contribution to the massless axion mass-shift is equal to zero while the virtual photon contribution is finite and can be of order of the recent restrictions on the axion mass.

Comments: 4 pages, latex2e, 2 PS figures, uses ws-p8-50x6-00.sty (included) and amssymb.sty. Talk at the International Workshop on Particle Physics and the Early Universe (COSMO-99), Trieste, Italy, 27 September - 3 October 1999