Anomalous baryon number non-conservation in the presence of SU(5) monopoles

Abstract

It is shown that the effects related to the Adler-Bell-Jackiw anomaly give rise to strong baryon number non-conservation in the presence of magnetic monopoles in the SU(5) grand unified theory. The main assumption made is that, as long as distances of order 1 GeV −1 from the monopole center are considered, the masses of light fermions u, d, s, e, μ can be neglected, while heavy fermions decouple. Two types of the SU(5) monopoles are studied, namely: (i) the fundamental monopole with a non-vanishing chromomagnetic charge, (ii) the minimal purely electromagnetic monopole. In both cases the processes like p+ monopole→ e ++ momopole+ everything are allowed. It is argued that the cross sections of these processes are of order 1 GeV −2 β −2, at least for sufficiently low monopole-proton relative velocities β.