A naturally light sterile neutrino in an asymmetric dark matter model

作者:Zhang, Yongchao*; Ji, Xiangdong; Mohapatra, Rabindra N
来源:The Journal of High Energy Physics, 2013, 2013(10): 104.
DOI:10.1007/JHEP10(2013)104

摘要

A recently proposed asymmetric mirror dark matter model where the mirror sector is connected with the visible one by a right-handed neutrino portal, is shown to lead naturally to a 3 1 active-sterile neutrino spectrum, if the portal consists only of two right-handed neutrinos. At tree level the model has four massless neutrino states, three (predominately) active and one sterile. The active neutrinos pick up tiny masses via the minimal radiative inverse seesaw mechanism at one-loop level. The loop effects also generate the large solar and atmospheric mixings, as well as the observed reactor mixing for certain ranges of parameters of the model. The dominant contribution to the sterile neutrino mass (similar to eV) arises from the gravitationally induced dimension-5 operators. Generating active-sterile mixing requires a two Higgs doublet extension of the standard model and a small mixing between the ordinary and mirror Higgs fields, which occurs naturally in mirror models.