The Rubakov-Callan Scattering on the Supergravity Monopole

TL;DR

This paper investigates the spectrum of small perturbations around a supersymmetric supergravity monopole, revealing an infinite tower of bound states and a fermion isospin flip effect similar to monopole catalysis phenomena.

Contribution

It provides the first detailed analysis of perturbation spectra and scattering effects in the supersymmetric supergravity monopole, highlighting novel bound states and isospin flip behavior.

Findings

Infinite Coulomb-type bound states in perturbation spectrum

Fermion scattering involves isospin flip, analogous to Rubakov-Callan effect

Eigenvalues are degenerate across bosonic and fermionic sectors due to supersymmetry

Abstract

We study small perturbations around the supersymmetric CVMN monopole solution of the gauged supergravity in D=4. We find that the perturbation spectrum contains an infinite tower of Coulomb-type bound states both in the bosonic and fermionic parts of the supergravity multiplet. Due to supersymmetry, the eigenvalues are the same for the two bosonic parity sectors, as well as for the fermionic sector. We also find that the fermion scattering on the monopole is accompanied by isospin flip. This is analogous to the Rubakov-Callan effect of monopole catalysis of proton decay and suggests that there could be a similar effect of catalysis for decay of fermionic systems in supergravity.