Warped Supersymmetry Breaking

TL;DR

This paper investigates how warping in higher-dimensional theories influences supersymmetry-breaking scales, revealing that warped geometries can significantly suppress the gravitino mass and affect low-energy SUSY phenomenology.

Contribution

It provides a detailed analysis of supersymmetry-breaking effects in warped extra dimensions, linking microscopic string theory calculations with 4D effective descriptions, and explores implications for moduli stabilization.

Findings

The lightest gravitino mass can be much less than naive estimates due to warping.

Warp factor e^A directly controls the gravitino mass and soft SUSY breaking terms.

Conditions for effective 4D supergravity descriptions are identified and limitations discussed.

Abstract

We address the size of supersymmetry-breaking effects within higher-dimensional settings where the observable sector resides deep within a strongly warped region, with supersymmetry breaking not necessarily localized in that region. Our particular interest is in how the supersymmetry-breaking scale seen by the observable sector depends on this warping. We obtain this dependence in two ways: by computing within the microscopic (string) theory supersymmetry-breaking masses in supermultiplets; and by investigating how warping gets encoded into masses within the low-energy 4D effective theory. We find that the lightest gravitino mode can have mass much less than the straightforward estimate from the mass shift of the unwarped zero mode. This lightest Kaluza-Klein excitation plays the role of the supersymmetric partner of the graviton and has a warped mass m_{3/2} proportional to e^A, with e^A the warp factor, and controls the size of the soft SUSY breaking terms. We formulate the conditions required for the existence of a description in terms of a 4D SUGRA formulation, or in terms of 4D SUGRA together with soft-breaking terms, and describe in particular situations where neither exist for some non-supersymmetric compactifications. We suggest that some effects of warping are captured by a linear $A$ dependence in the Kahler potential. We outline some implications of our results for the KKLT scenario of moduli stabilization with broken SUSY.