Neutrino Anomalies in Gauge Mediated Model with Trilinear R violation

Abstract

The structure of neutrino masses and mixing resulting from trilinear $R$ violating interactions is studied in the presence of the gauge mediated supersymmetry breaking. Neutrino masses arise in this model at tree level through the RG-induced vacuum expectation values of the sneutrinos and also through direct contribution at 1-loop. The relative importance of these contributions is determined by the values of the strong and weak coupling constants. In case of purely $λ'$ couplings, the tree contribution dominates over the 1-loop diagram. In this case, one simultaneously obtains atmospheric neutrino oscillations and quasi-vacuum oscillations of the solar neutrinos if all the $ł'$ couplings are assumed to be of similar magnitudes. If R parity violation arises from the trilinear $ł$ couplings, then the loop induced contribution dominates over the tree level. One cannot simultaneously explain the solar and atmospheric deficit in this case if all the $ł$ couplings are of similar magnitude. This however becomes possible with hierarchical $ł$ and we give a specific example of this.

26 pages Latex, 2 figures, certain sections rewritten, improved discussion about derivations added. To appear in Physical Review D