Modified majoron model for cosmological anomalies

Abstract

The vacuum expectation value of a Higgs triplet field carrying two units of lepton number induces neutrino masses . The neutral component of gives rise to two Higgs particles, a pseudoscalar and a scalar . The most general renormalizable Higgs potential for and the Standard-Model Higgs doublet does not permit the possibility that the mass of either or is small, of order , while the other mass is heavy enough to forbid the decay to comply with LEP 1 data. We present a model with additional dimension-6 terms in , in which this feature is absent and either or can be chosen light. Subsequently we propose the model as a remedy to cosmological anomalies, namely the tension between observed and predicted tensor-to-scalar mode ratios in the cosmic microwave background and the different values of the Hubble constant measured at different cosmological scales. Furthermore, if dominantly couples to the third-generation doublet , the deficit of events at IceCube can be explained. The singly and doubly charged triplet Higgs bosons are lighter than 280 GeV and 400 GeV, respectively, and could be found at the LHC.