Probing neutrino and Higgs sectors in $SU(2)_1 \times SU(2)_2 \times U(1)_Y$ model with lepton-flavor non-universality

TL;DR

This paper explores an extended gauge model with lepton-flavor non-universality, showing how neutrino masses can arise radiatively with new Higgs bosons, and analyzes the Higgs sector's properties, mixing, and experimental implications.

Contribution

It introduces a novel mechanism for neutrino mass generation via radiative corrections in an extended gauge model with new Higgs fields, and studies the Higgs sector's detailed properties and experimental signatures.

Findings

Active neutrinos acquire Majorana masses radiatively.

The Higgs sector's mass matrices are proportional to the triple Higgs coupling coefficient.

The SM-like Higgs couplings deviate slightly from SM predictions, consistent with experimental data.

Abstract

The neutrino and Higgs sectors in the $\mbox{SU(2)}_1 \times \mbox{SU(2)}_2 \times \mbox{U(1)}_Y $ model with lepton-flavor non-universality are discussed. We show that active neutrinos can get Majorana masses from radiative corrections, after adding only new singly charged Higgs bosons. The mechanism for generation of neutrino masses is the same as in the Zee models. This also gives a hint to solving the dark matter problem based on similar ways discussed recently in many radiative neutrino mass models with dark matter. Except the active neutrinos, the appearance of singly charged Higgs bosons and dark matter does not affect significantly the physical spectrum of all particles in the original model. We indicate this point by investigating the Higgs sector in both cases before and after singly charged scalars are added into it. Many interesting properties of physical Higgs bosons, which were not shown previously, are explored. In particular, the mass matrices of charged and CP-odd Higgs fields are proportional to the coefficient of triple Higgs coupling $\mu$. The mass eigenstates and eigenvalues in the CP-even Higgs sector are also presented. All couplings of the SM-like Higgs boson to normal fermions and gauge bosons are different from the SM predictions by a factor $c_h$, which must satisfy the recent global fit of experimental data, namely $0.995<|c_h|<1$. We have analyzed a more general diagonalization of gauge boson mass matrices, then we show that the ratio of the tangents of the $W-W'$ and $Z-Z'$ mixing angles is exactly the cosine of the Weinberg angle, implying that number of parameters is reduced by 1. Signals of new physics from decays of new heavy fermions and Higgs bosons at LHC and constraints of their masses are also discussed.