Neutrino Masses in the Supersymmetric Standard Model with Right-Handed Neutrinos and Spontaneous R-Parity Violation

TL;DR

This paper introduces an extended supersymmetric model with right-handed neutrinos and a singlet Higgs, explaining neutrino masses and mixings through combined seesaw and R-parity violation effects.

Contribution

It proposes a novel supersymmetric model incorporating right-handed neutrinos and spontaneous R-parity violation, providing a unified explanation for neutrino masses and oscillations.

Findings

Neutrino masses arise from seesaw and R-parity breaking effects.

The model reproduces observed solar and atmospheric neutrino oscillations.

Hierarchical neutrino mass pattern is achieved without hierarchical Yukawa matrices.

Abstract

We propose an extension of the supersymmetric standard model with right-handed neutrinos and a singlet Higgs field, and study the neutrino masses in this model. The Majorana masses for the right-handed neutrinos are generated around the supersymmetry breaking scale through the vacuum expectation value of the singlet Higgs field. This model may induce spontaneous R-parity violation via the vacuum expectation value of the right-handed sneutrino. In the case, the effective theory is similar to a bilinear R-parity violating model. There are two sources for the neutrino masses: one is this bilinear R-parity breaking effect, and the other is the ordinary seesaw effect between left- and right-handed neutrinos. Combining these two effects, the hierarchical neutrino mass pattern arises even when the neutrino Yukawa matrices are not hierarchical. We acquire appropriate masses and mixings to explain both the solar and atmospheric neutrino oscillations.