Massive higher dimensional gauge fields as messengers of supersymmetry breaking

Abstract

We consider theories with one or more compact dimensions with size r > 1/M, where M is the fundamental Planck scale, with the visible and hidden sectors localized on spatially separated '3-branes.' We show that a bulk U(1) gauge field spontaneously broken on the hidden-sector 3-brane is an attractive candidate for the messenger of supersymmetry breaking. In this scenario scalar mass-squared terms are proportional to U(1) charges, and therefore naturally conserve flavor. Arbitrary flavor violation at the Planck scale gives rise to exponentially suppressed flavor violation at low energies. Gaugino masses can be generated if the standard gauge fields propagate in the bulk; µ and Bµ terms can be generated by the Giudice-Masiero or by the VEV of a singlet in the visible sector. The latter case naturally solves the SUSY CP problem. Realistic phenomenology can be obtained either if all microscopic parameters are order one in units of M, or if the theory is strongly coupled at the scale M. In either case, the only unexplained hierarchy is the 'large' size of the extra dimensions in fundamental units, which need only be an order of magnitude. All soft masses are naturally within an order of magnitude of m 3/2 , and trilinear scalar couplings are negligible. Squark and slepton masses can naturally unify even in the absence of grand unification. *

Anomalous gauge couplings from composite Higgs and warped extra dimensions

“…This quantity is sensitive to the details of the model, including the realization of the custodial sector. 21 8 Probing a warped extra dimension using anomalous gauge couplings…”

The gravitino in gaugino mediation

“…4 shows the ratio of theτ R and the bino mass at the electroweak scale calculated in a crude approximation: Mixing has been neglected, and only the terms proportional to M 2 1 and m 2 τ R in Eq. (22) have been taken into account. We have chosen tan β = 10, m 1/2 (M c ) = 400 GeV and m 2…”

Flavor hierarchy from extra dimension and gauge threshold correction

“…In orbifold GUT which is strongly coupled at Λ, g 2 5a and γ a are universal as a consequence of unified gauge symmetry in bulk, and both κ a and κ ′ a are of the order of 1/8π 2 as the theory is strongly coupled at Λ [29,30]. We then have…”