Axino as a sterile neutrino and R parity violation

Abstract

We suggest that the axino can be a natural candidate for a sterile neutrino which would accommodate the LSND data with atmospheric and solar neutrino oscillations. It is shown that the so-called 3 + 1 scheme can be easily realized when supersymmetry breaking is mediated by gauge interactions and also R parity is properly broken. Among the currently possible solutions to the solar neutrino problem, only the large angle MSW oscillation is allowed in this scheme. The weak scale value of the Higgs mu parameter and the required size of R-parity violation can be understood by means of spontaneously broken Peccei-Quinn symmetry.