Speaker
Description
Abstract
Onur Yonar
The electromagnetic properties of Majorana fermions are stringently constrained, allowing only
the presence of an anapole moment. We investigate the radiative interactions of spin-3/2 Majorana
fermions with the photon. From supergravity, the gravitino emerges as a prototypical example
of such a particle. We calculate one-loop form factors of the LSP gravitino in N = 1 broken
supergravity. Furthermore, the general interactions between spin-3/2 fermions and lower-spin
particles are explored, revealing stringent constraints on renormalisable models. Based on our
findings, we construct a unique minimal model, which generates an anapole moment through
renormalisable Yukawa couplings. Spin-3/2 fermions are natural candidates for dark matter. We
conclude with a discussion of the implications of the anapole interactions for the direct detection
of massive Majorana spin-3/2 dark matter.
