Big-bang nucleosynthesis and Leptogenesis in CMSSM

TL;DR

This paper explores the parameter space of the CMSSM with right-handed neutrinos to simultaneously address Leptogenesis, dark matter, and the Lithium problem, identifying narrow conditions that satisfy all constraints.

Contribution

It identifies a specific narrow parameter region in CMSSM with right-handed neutrinos that can solve the Lithium problem while being consistent with Leptogenesis and dark matter.

Findings

Narrow parameter space where the lightest slepton has a long lifetime

Mass range of right-handed neutrino between 10^9 and 10^11 GeV

Predicted low-energy observables are within future experimental reach

Abstract

We have investigated the constrained minimal supersymmetric standard model with three right-handed Majorana neutrinos whether there still is a parameter region which is consistent with all existing experimental data/limits such as Leptogenesis and the dark matter abundance and we also can solve the Lithium problem. Using Casas-Ibarra parameterization, we have found that a very narrow parameter space of the complex orthogonal matrix elements where the lightest slepton can have a long lifetime, that is necessary for solving the Lithium problem. Further, under this condition, there is a parameter region that can give an explanation for the experimental observations. We have studied three cases of the right-handed neutrino mass ratio \mbox{\em (i)} $M_{2}=2 \times M_{1}$, \mbox{\em (ii)} $M_{2}=4 \times M_{1}$, \mbox{\em (iii)} $M_{2}=10 \times M_{1}$ while $M_{3}=40 \times M_{1}$ is fixed. We have obtained the mass range of the lightest right-handed neutrino mass that lies between $10^9$ GeV and $10^{11}$ GeV. The important result is that its upper limit is derived by solving the Lithium problem and the lower limit comes from Leptogenesis. Calculated low-energy observables of these parameter sets such as BR($\mu \to e \gamma$) is not yet restricted by experiments and will be verified in the near future.