Realistic neutrinogenesis with radiative vertex correction

Gu, Pei-Hong ; He, Hong-Jian ; Sarkar, Utpal (2008) Realistic neutrinogenesis with radiative vertex correction Physics Letters B, 659 (3). pp. 634-639. ISSN 0370-2693

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Official URL: http://www.sciencedirect.com/science/article/pii/S...

Related URL: http://dx.doi.org/10.1016/j.physletb.2007.11.061

Abstract

We propose a new model for naturally realizing light Dirac neutrinos and explaining the baryon asymmetry of the universe through neutrinogenesis. To achieve these, we present a minimal construction which extends the standard model with a real singlet scalar, a heavy singlet Dirac fermion and a heavy doublet scalar besides three right-handed neutrinos, respecting lepton number conservation and a Z2 symmetry. The neutrinos acquire small Dirac masses due to the suppression of weak scale over a heavy mass scale. As a key feature of our construction, once the heavy Dirac fermion and doublet scalar go out of equilibrium, their decays induce the CP asymmetry from the interference of tree-level processes with the radiative vertex corrections (rather than the self-energy corrections). Although there is no lepton number violation, an equal and opposite amount of CP asymmetry is generated in the left-handed and the right-handed neutrinos. The left-handed lepton asymmetry would then be converted to the baryon asymmetry in the presence of the sphalerons, while the right-handed lepton asymmetry remains unaffected.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:45429
Deposited On:28 Jun 2011 05:29
Last Modified:18 May 2016 01:42

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