A unique Z_4^R symmetry for the MSSM
Abstract
We consider the possible anomaly free Abelian discrete symmetries of the MSSM that forbid the mu-term at perturbative order. Allowing for anomaly cancellation via the Green-Schwarz mechanism we identify discrete R-symmetries as the only possibility and prove that there is a unique Z_4^R symmetry that commutes with SO(10). We argue that non-perturbative effects will generate a mu-term of electroweak order thus solving the mu-problem. The non-perturbative effects break the Z_4^R symmetry leaving an exact Z_2 matter parity. As a result dimension four baryon- and lepton-number violating operators are absent while, at the non-perturbative level, dimension five baryon- and lepton-number violating operators get induced but are highly suppressed so that the nucleon decay rate is well within present bounds.
Cite
@article{arxiv.1009.0905,
title = {A unique Z_4^R symmetry for the MSSM},
author = {Hyun Min Lee and Stuart Raby and Michael Ratz and Graham G. Ross and Roland Schieren and Kai Schmidt-Hoberg and Patrick K. S. Vaudrevange},
journal= {arXiv preprint arXiv:1009.0905},
year = {2011}
}
Comments
6 pages