Retrofitted Natural Supersymmetry from a U(1)
ArXiv 1302.5423 (2013)
Authors:
Edward Hardy, John March-Russell
Abstract:
We propose that a single, spontaneously broken, U(1) gauge symmetry may be
responsible for suppressing both the first two generation Yukawa couplings, and
also, in a correlated manner, parameters in the dynamical supersymmetry (SUSY)
breaking sector by the mechanism of retrofitting. In the dynamical SUSY
breaking sector, these small parameters are typically required in order to
introduce R-symmetry breaking in a controlled manner and obtain
phenomenologically viable meta-stable vacua. The heavy U(1) multiplet mediates
a dominant contribution to the first two generation MSSM sfermion soft masses,
while gauge mediation provides a parametrically suppressed soft term
contribution to the stop and most other states, so realising a natural SUSY
spectrum in a fashion consistent with SUSY unification. In explicit models the
spectra obtained can be such that current LHC limits are evaded, and
predictions of flavour changing processes are consistent with observation. We
examine both implementations with low scale mediation, and string-motivated
examples where the U(1) is anomalous before the inclusion of a generalised
Green-Schwarz mechanism.
