Effective Lagrangians and Light Gravitino Phenomenology
Abstract
We construct the low-energy effective lagrangian for a light gravitino coupled to the minimal supersymmetric standard model under the assumption that supersymmetry breaking is communicated to the observable sector dominantly through soft terms. Our effective lagrangian is written in terms of the spin-1/2 Goldstino (the longitudinal component of the gravitino) transforming under a non-linear realization of supersymmetry. In this lagrangian, the Goldstino is derivatively coupled and all couplings of the Goldstino to light fields are determined uniquely by the supersymmetry-breaking scale \sqrt{F}. This lagrangian is therefore a useful starting point for further investigation of the light gravitino in gauge-mediated supersymmetry breaking models. We show that the invisible width of the Z into Goldstinos gives the constraint \sqrt{F} > 140 GeV.
Keywords
Cite
@article{arxiv.hep-ph/9706268,
title = {Effective Lagrangians and Light Gravitino Phenomenology},
author = {Markus A. Luty and Eduardo Ponton},
journal= {arXiv preprint arXiv:hep-ph/9706268},
year = {2009}
}
Comments
15 pages, LaTeX2e, 1 eps figure. Removed erroneous claim of coupling of photon to gravitino to photons at order M^2 E^2 / F^2. Strongest bound is from invisible Z width, giving F > (140 GeV)^2