R-parity Violating Right-Handed Neutrino in Gravitino Dark Matter Scenario

TL;DR

This paper proposes a model where tiny R-parity violation in the right-handed neutrino sector allows gravitino dark matter decay, explaining cosmic-ray excesses while maintaining successful thermal leptogenesis.

Contribution

It introduces a novel R-parity violation mechanism in the right-handed neutrino sector suppressed by a see-saw, enabling gravitino decay and consistent leptogenesis.

Findings

Gravitino decay can explain cosmic-ray excesses.

R-parity violation is sufficiently suppressed by see-saw.

Thermal leptogenesis remains viable with this mechanism.

Abstract

A decay of the gravitino dark matter is an attractive candidate to explain the current excesses of the PAMELA/ATIC cosmic-ray data. However, R-parity violations are required to be very tiny in low-energy scale. We suggest a R-parity violation in the right-handed neutrino sector. The violation is suppressed by a see-saw mechanism. Although a reheating temperature is constrained from above, the thermal leptogenesis is found to work successfully with a help of the R-parity violating right-handed neutrino.