Some phenomenological studies of a U(1)_R — lepton number model with a right handed neutrino

We discuss the Higgs sector and neutrino mass and mixing in the context of a supersymmetric model with a U(1)_R symmetry augmented by a single right handed neutrino superfield. The lepton number of the standard model fermions are identified with the negative of their R-charges. The presence of the neutrino Yukawa coupling (f) plays a very interesting role in Dirac neutrino mass generation as well as providing a tree level correction to the Higgs boson mass, when f ∼ O(1). In order to fit the complete neutrino mass and mixing, a small breaking of the U(1)_R symmetry is considered in the context of anomaly mediated supersymmetry breaking. We also show that when f ∼ 10^-4, the right handed neutrino can be identified with a 7 keVsterile neutrino dark matter as recent studies have speculated. (paper)