Supersymmetric leptogenesis and light hidden sectors

TL;DR

This paper explores solutions to the conflicts between thermal leptogenesis, supergravity, and primordial nucleosynthesis by introducing light hidden sectors or condensates that alter decay channels of long-lived particles.

Contribution

It proposes and compares two novel mechanisms involving hidden sectors to resolve primordial nucleosynthesis issues in supersymmetric leptogenesis models.

Findings

Hidden sectors can provide new decay channels to avoid BBN conflicts.

Dynamical matter parity breaking in hidden sectors offers an alternative solution.

The scenarios improve compatibility of leptogenesis with supergravity constraints.

Abstract

Thermal leptogenesis and supergravity are attractive scenarios for physics beyond the standard model. However, it is well known that the super-weak interaction of the gravitino often leads to problems with primordial nucleosynthesis in the standard scenario of matter parity conserving MSSM + three right-handed neutrinos. We will present and compare two related solutions to these problems: 1) The conflict between BBN and leptogenesis can be avoided in presence of a hidden sector with light supersymmetric particles which open new decay channels for the dangerous long-lived particles. 2) If there is a condensate in the hidden sector, such additional decay channels can be alternatively opened by dynamical breaking of matter parity in the hidden sector.