Hidden from view: Neutrino masses, dark matter, and TeV-scale leptogenesis in a neutrinophilic two-Higgs-doublet model
We consider a simple extension of the Standard Model providing dark matter and a TeV-scale seesaw mechanism that also allows for viable leptogenesis. In addition to the Standard Model degrees of freedom, the model contains a neutrinophilic Higgs doublet, a scalar singlet, and six singlet fermions (including three right-handed Majorana neutrinos) that are charged under a local U(1)′ gauge symmetry. We show how the U(1)′ charge assignments and the choice of scalar potential can lead to a TeV-scale seesaw mechanism and O(1) neutrino Yukawa couplings in a straightforward way. While this scenario has all the ingredients one would expect for significant experimental signatures, including several new TeV-scale degrees of freedom, we find that most distinctive features associated with neutrino mass generation, leptogenesis and the dark sector are likely to remain inaccessible in the absence of additional lepton flavor symmetries.
Additional Information© 2014 American Physical Society. Received 26 May 2013; revised manuscript received 22 December 2013; published 14 February 2014. We thank O. Seto for alerting us to the potential importance of the ΔL = 2 washout processes. This work was supported in part by DOE Contract No. DE-FG02-08ER41531 and the Wisconsin Alumni Research Foundation.
Published - PhysRevD.89.033007.pdf