Low-Energy Brane-World Effective Actions and Partial Supersymmetry Breaking

TL;DR

This paper explores the low-energy effects of supersymmetry breaking in brane-world models, deriving effective actions and transformation rules for N=1 supergravity scenarios with different brane configurations.

Contribution

It provides a model-independent derivation of effective actions for N=1 supergravity from N=2 breaking, revealing direct brane-brane contact interactions contrary to sequestering predictions.

Findings

Derivation of minimal field content and effective actions for N=1 supergravity

Identification of direct brane-brane contact interactions at order O(kappa)

Contradiction of sequestering scenario predictions with new contact interaction results

Abstract

As part of a programme for the general study of the low-energy implications of supersymmetry breaking in brane-world scenarios, we study the nonlinear realization of supersymmetry which occurs when breaking N=2 to N=1 supergravity. We consider three explicit realizations of this supersymmetry breaking pattern, which correspond to breaking by one brane, by one antibrane or by two (or more) parallel branes. We derive the minimal field content, the effective action and supersymmetry transformation rules for the resulting N=1 theory perturbatively in powers of kappa = 1/M_{Planck}. We show that the way the massive gravitino and spin-1 fields assemble into N=1 multiplets implies the existence of direct brane-brane contact interactions at order O(kappa). This result is contrary to the O(kappa^2) predicted by the sequestering scenario but in agreement with recent work of Anisimov et al. Our low-energy approach is model independent and is a first step towards determining the low-energy implications of more realistic brane models which completely break all supersymmetries.