Leptogenesis in supersymmetry with one L violating coupling

Rathin Adhikari,Arnab Dasgupta

doi:10.1140/epjc/s10052-021-09406-z

Abstract

We have shown a new scenario of successful leptogenesis with one L violating coupling and a relative Majorana phase playing the role of CP violation. This is in contrast to the usual consideration of Feynman diagram with at least two L violating couplings. We have considered R-parity violating minimal supersymmetric standard model (MSSM) for leptogenesis at TeV scale. This scenario is also consistent with generating light neutrino mass if asymmetry is generated through semileptonic lambda ^{prime } coupling.

Highlights

There is asymmetry in the number density of baryons (n B ) and antibaryons (n B ) in our observed universe [1,2] and one may consider baryogenesis or leptogenesis mechanism [3] to explain such asymmetry
We have considered leptogenesis mechanism in the context of R parity violating Minimal Supersymmetric Standard model where next to lightest neutralino could have this property of having both L violating and L conserving decay modes as shown in Figs. 1 and 2
B or L violating coupling should be present on the right of the ‘cut’ in the higher order diagram (‘cut’ on the internal line is possible when on-shell condition is satisfied indicating presence of imaginary part of loop integral which is required for C P asymmetry) with net change in B or L due to all such couplings on the right with final states

Summary

Introduction

There is asymmetry in the number density of baryons (n B ) and antibaryons (n B ) in our observed universe [1,2] and one may consider baryogenesis or leptogenesis mechanism [3] to explain such asymmetry. B or L violating coupling should be present on the right of the ‘cut’ in the higher order diagram (‘cut’ on the internal line is possible when on-shell condition is satisfied indicating presence of imaginary part of loop integral which is required for C P asymmetry) with net change in B or L due to all such couplings on the right with final states. This is essential to have non-vanishing total B or L asymmetry after summing over all possible intermediate and final states generated due to decay.

Low scale leptogenesis in MSSM

30 TeV 7 TeV

Conclusion