Dark Matter and Baryogenesis from Non-Abelian Gauged Lepton Number

Abstract

A simple model is constructed based on the gauge symmetry $SU(3{)}_c\times SU(2{)}_L\times U(1{)}_Y\times SU(2{)}_{\ell }$, with only the leptons transforming nontrivially under $SU(2{)}_{\ell }$. The extended symmetry is broken down to the Standard Model gauge group at TeV-scale energies. We show that this model provides a mechanism for baryogenesis via leptogenesis in which the lepton number asymmetry is generated by $SU(2{)}_{\ell }$ instantons. The theory also contains a dark matter candidate - the $SU(2{)}_{\ell }$ partner of the right-handed neutrino.

Comments: 17 pages, 5 figures; Plenary talk given at the Conference on Cosmology, Gravitational Waves and Particles, Singapore, February 6-10, 2017; based on arXiv:1703.00199 [hep-ph]