Atomki anomaly and dark matter in a radiative seesaw model with gauged $B-L$ symmetry

TL;DR

This paper proposes a radiative seesaw model with gauged B-L symmetry to explain the Atomki anomaly and dark matter, predicting a light dark matter candidate below 10 GeV compatible with experimental data.

Contribution

It introduces a novel radiative seesaw model with gauged B-L symmetry that links the Atomki anomaly to dark matter phenomenology and predicts detectable signals in direct detection experiments.

Findings

The model can explain the Atomki anomaly with a B-L gauge boson decay.

The dark matter candidate mass is constrained below 10 GeV.

Predicted spin-independent cross section is testable in future experiments.

Abstract

Motivated by recently reported anomalies in a decay of an excited state of beryllium by the Atomki collaboration, we study a radiative seesaw model with gauged $B-L$ symmetry and a $Z_2$ parity. Assuming that the anomalies originate from the decay of the $B-L$ gauge boson followed by the nuclear decay, the mass of the lightest right-handed neutrino or the dark matter candidate can be determined below $10$ GeV. We show that for this mass range, the model can explain the anomalies in the beryllium decay and the relic dark matter abundance consistent with neutrino masses. We also predict its spin-independent cross section in direct detection experiments for this mass range.