Electron EDM and soft leptogenesis in supersymmetric B-L extension of the standard model

TL;DR

This paper explores how the supersymmetric B-L extension of the standard model links the electron's electric dipole moment with soft leptogenesis, highlighting that certain phases are unconstrained by current bounds and proposing testable scenarios.

Contribution

It demonstrates that in the supersymmetric B-L model, phases relevant for leptogenesis are not limited by EDM bounds and identifies a promising scenario with non-universal A-terms for future experimental tests.

Findings

Electron EDM bounds do not constrain phases for soft leptogenesis.

Successful leptogenesis requires small B-terms related to A_N and B-L breaking.

Future EDM experiments can test the proposed leptogenesis scenario.

Abstract

We analyze the connection between electric dipole moment of the electron and the soft leptogenesis in supersymmetric $B-L$ extension of the standard model. In this model, the $B-L$ symmetry is radiatively broken at TeV scale. Therefore, it is a natural framework for low scale seesaw mechanism and also for implementing the soft leptogenesis. We show that the phases of trilinear soft SUSY breaking couplings $A$, which are relevant for the lepton asymmetry, are not constrained by the present experimental bounds on electric dipole moment. As in the MSSM extended with right-handed neutrinos, successful leptogenesis requires small bilinear coupling $B$, which is now given by $A_N$ and $B-L$ breaking VEVs. SUSY $B-L$ model with non-universal $A$-terms such that $A_N=0$ while $A_{\nu}\neq0$ is a promising scenario for soft leptogenesis. The proposed EDM experiments will test this scenario in the future.