Heavy Gravitino from Dynamical Generation of Right-Handed Neutrino Mass Scale, and Gravitational Waves

TL;DR

This paper explores how right-handed neutrino masses generated by hidden gaugino condensation can influence gravitino mass bounds, potentially explain the little hierarchy problem, and produce observable gravitational waves from domain wall annihilation.

Contribution

It proposes a novel mechanism linking right-handed neutrino mass generation to gravitino mass bounds and gravitational wave signals from domain walls.

Findings

Lower bound on gravitino mass from leptogenesis

Potential gravitational wave signals from domain wall annihilation

Connection between neutrino mass scale and hierarchy problem

Abstract

The absence of supersymmetric particles at the weak scale is a puzzle if supersymmetry solves the gauge hierarchy problem. We show that, if the right-handed neutrino masses arise from hidden gaugino condensation via GUT-suppressed operators, successful thermal leptogenesis leads to the lower bound on the gravitino mass, which may explain the little hierarchy problem. If domain walls associated with the gaugino condensation are formed after inflation, they annihilate when $H \sim m_{3/2}$. We address the possibility that observable gravitational wave signals might emerge from the domain wall annihilation.