Aula Conversi, Roma 1

I will discuss the mediation of supersymmetry breaking in sequestered models, where the visibile and the hidden sectors are separated along an extra dimension and soft breaking terms arise through loop effects. I will focus on the simplest case of an S^1/Z_2 orbifold, with matter fields localized at the two four-dimensional fixed points and gauge or gravitational fields propagating in the five-dimensional bulk. Using the off-shell formulation of global and local supersymmetry in five dimensions, I will derive the bulk-to-boundary couplings and illustrate through simple examples the structure of loop corrections. I will then apply these general results to compute the radius-dependent contribution to sfermion masses induced by loops of bulk gravitational fields, which can compete with the radius-independent anomaly-mediated contribution induced by loops of localized matter fields. I will finally comment on the possibility of constructing viable sequestered models with positive flavour-universal sfermion squared masses.