Domain walls and CP violation with left right supersymmetry: implications for leptogenesis and electron EDM

Abstract

Low scale leptogenesis scenarios are difficult to verify due to our inability to relate the parameters involved in the early universe processes with the low energy or collider observables. Here we show that one can in principle relate the parameters giving rise to the transient CP violating phase involved in leptogenesis with those that can be deduced from the observation of electric dipole moment (EDM) of the electron. We work out the details of this in the context of the left right symmetric supersymmetric model (LRSUSY) which provides a strong connection between such parameters. In particular, we show that baryon asymmetry requirements imply the scale MB−L of U(1)B−L symmetry breaking to be larger than 104.5 GeV. Moreover the scale MR of SU(2)R symmetry breaking is tightly constrained to lie in a narrow band significantly below $$ {M}_{B-L}^2/{M}_{EW} $$ M B − L 2 / M EW . These are the most stringent constraints on the parameter space of LRSUSY model being considered.

Gravitational wave signature of generic disappearance of $Z_2$-symmetry breaking domain walls

“…This requirement has been discussed in detail in [16][17][18][19]. It has also been shown that domain walls in SUSYLR can be successfully exploited for baryogenesis via leptogenesis while remaining consistent with low energy observables like the electric dipole moment of the electron, with a gravitational wave signature that can be detected in upcoming experiments [20]. More recent works like [21][22][23][24] have studied the gravitational wave consequences of bubble wall and/or domain wall collapse in LRSM, where the domain wall collapse is initiated by adding tiny explicit terms breaking the discrete leftright symmetry.…”