Scalar Dark Matter and Radiative Dirac neutrino mass in an extended $U(1)_{B-L}$ model

TL;DR

This paper proposes a $U(1)_{B-L}$ extended model with exotic charges that generates Dirac neutrino masses radiatively and includes a scalar dark matter candidate stabilized by a $Z_2$ symmetry, with phenomenological implications for dark matter detection and lepton flavor violation.

Contribution

It introduces a novel $U(1)_{B-L}$ extension with exotic charges that enables radiative Dirac neutrino mass generation and incorporates a dark matter candidate stabilized by a $Z_2$ symmetry.

Findings

Radiative Dirac neutrino masses are successfully generated.

Scalar dark matter relic density is governed by co-annihilation processes.

Model satisfies constraints from lepton flavor violating decays.

Abstract

We explore a gauged $U(1)_{B-L}$ extension of standard model with inclusion of three right-handed neutrinos of exotic $B-L$ charges to cancel the gauge anomaly. Non-trivial transformation of new particles under $B-L$ symmetry forbids the neutrino mass at tree level and hence a small Dirac mass can be generated radiatively at one loop with a doublet fermion and singlet scalar. We also discuss the phenomenology of a scalar dark matter, which can be obtained from the mixing of neutral CP even component of a doublet and real singlet scalar. An adhoc $Z_2$ symmetry is required in the current framework to stabilize the dark matter candidate. Presence of new particles with $Z_2$ odd charges and small mass splitting, makes the phenomenology more interesting by governing the relic density with co-annihilation processes. We explore the spin-independent direct detection constraints on dark matter via the scalar mediation. The new particle spectrum not only opens up new window for dark matter study but also satisfy the constraints from lepton flavor violating decay of $\mu \rightarrow e \gamma$.