Canonical seesaw implication for two-component dark matter

TL;DR

This paper proposes a two-component dark matter model derived from the canonical seesaw mechanism with $U(1)_{B-L}$ symmetry, explaining recent anomalies and predicting specific mass and charge properties for the dark matter particles.

Contribution

It introduces a natural two-component dark matter framework from the $U(1)_{B-L}$ seesaw mechanism, highlighting a residual $Z_6$ symmetry and its implications.

Findings

Dark matter components transform under matter parity and $Z_3$.

The model can explain the XENON1T anomaly.

Dark matter particles can have arbitrary masses, with specific charge properties.

Abstract

We show that the canonical seesaw mechanism implemented by the $U(1)_{B-L}$ gauge symmetry provides two-component dark matter naturally. The seesaw scale that breaks $B-L$ defines a residual gauge symmetry to be $Z_6=Z_2\otimes Z_3$, where $Z_2$ leads to the usual matter parity, while $Z_3$ is newly recognized, transforming quark fields nontrivially. The dark matter components -- that transform nontrivially under the matter parity and $Z_3$, respectively -- can gain arbitrary masses, despite the fact that the $Z_3$ dark matter may be heavier than the light quarks $u,d$. This dark matter setup can address the XENON1T anomaly recently observed and other observables, given that the dark matter masses are nearly degenerate, heavier than the electron and the $B-L$ gauge boson $Z'$, as well as the fast-moving $Z_3$ dark matter has a large $B-L$ charge, while the $Z'$ is viably below the beam dump experiment sensitive regime.