Dark matter indirect detection signals and the nature of neutrinos in the supersymmetric $U(1)_{B-L}$ extension of the standard model

TL;DR

This paper explores how dark matter signals and cosmic microwave background data can reveal whether neutrinos are Majorana or Dirac particles within a supersymmetric $U(1)_{B-L}$ extension of the standard model.

Contribution

It introduces a model with two dark matter candidates and demonstrates how indirect detection signals can distinguish neutrino types and provide insights into the model's nature.

Findings

Majorana neutrinos produce distinctive neutrino and gamma-ray spectral features.

Dirac neutrinos contribute detectably to the effective number of neutrinos, $N_{eff}$.

Dark matter signals can help determine the neutrino nature in the $B-L$ extended model.

Abstract

In this paper, we study the prospects for determining the nature of neutrinos in the context of a supersymmetric $B-L$ extension of the standard model by using dark matter indirect detection signals and bounds on $N_{\text{eff}}$ from the cosmic microwave background data. The model contains two new dark matter candidates whose dominant annihilation channels produce more neutrinos than neutralino dark matter in the minimal supersymmetric standard model. The photon and neutrino counts may then be used to discriminate between the two models. If the dark matter comes from the B-L sector, its indirect signals and impact on the cosmic microwave background can shed light on the nature of the neutrinos. When the light neutrinos are of Majorana type, the indirect neutrino signal from the Sun and the galactic center may show a prompt neutrino box-feature, as well as an earlier cut-off in both neutrino and gamma ray energy spectra. When the light neutrinos are of Dirac type, their contribution to the effective number of neutrinos $N_{\text{eff}}$ is at a detectable level.