Gravitational quantum corrections in warped supersymmetric brane worlds

Abstract

We study gravitational quantum corrections in supersymmetric theories with warped extra dimensions. We develop for this a superfield formalism for linearized gauged supergravity. We show that the 1-loop effective Kähler potential is a simple functional of the KK spectrum in the presence of generic localized kinetic terms at the two branes. We also present a simple understanding of our results by showing that the leading matter effects are equivalent to suitable displacements of the branes. We then apply this general result to compute the gravity-mediated universal soft mass m 2 0 in models where the visible and the hidden sectors are sequestered at the two branes. We find that the contributions coming from radion mediation and brane-to-brane mediation are both negative in the minimal set-up, but the former can become positive if the gravitational kinetic term localized at the hidden brane has a sizable coefficient. We then compare the features of the two extreme cases of flat and very warped geometry, and give an outlook on the building of viable models.

On the one-loop Kähler potential in five-dimensional brane-world supergravity

“…On the other hand, any couplings in ∆Ω that are different than those in the tree-level Kähler potential correspond necessarily to non-local operators in 5d theory and therefore they should be finite and UV insensitive. Reference [6] derives a very useful expression for ∆Ω,…”

“…For N V = N H = 0 this formula is equivalent to that in ref. [6] with the momentum integral evaluated using dimensional regularization. We now apply the general formula (30) to the model considered in this paper.…”

“…The brane-world action considered in refs. [3,4,5,6] was based on an off-shell formulation of 5d supergravity. In this paper we point out that the physics of 5d brane-worlds can be studied in a simpler set-up of on-shell supergravity.…”

Mediation of Supersymmetry Breaking in Extra Dimensions

“…[19] and [22], consists instead in using the linearized superfield approach of ref. [24] or the generalization to the warped case of [22], and perform a supergraph computation. But happily, after some supergravity gymnastics the corrections we are interested can be mapped to the effective action of a very simple theory involving a single real scalar degree of freedom propagating in the same geometry and possessing localized kinetic terms at the two branes.…”

“…We will not give here a rigourous proof of this fact, for which we refer the interested reader to ref. [22], but rather some qualitative hints on the basic properties behind it. The main ingredients of the computation are the interactions between the brane and the bulk fields.…”