Freezing In with Lepton Flavored Fermions

TL;DR

This paper explores dark, lepton-flavored fermions as freeze-in dark matter candidates, highlighting their stability, interactions, and potential signals in future direct detection experiments.

Contribution

It introduces a minimal flavor violation framework for lepton-flavored fermions, analyzing their stability and experimental signatures in direct detection experiments.

Findings

Stable particles under certain flavor representations.

Detectable signals at future experiments like DARWIN.

Current experiments like XENON1T already probe some models.

Abstract

Dark, chiral fermions carrying lepton flavor quantum numbers are natural candidates for freeze-in. Small couplings with the Standard Model fermions of the order of lepton Yukawas are `automatic' in the limit of Minimal Flavor Violation. In the absence of total lepton number violating interactions, particles with certain representations under the flavor group remain absolutely stable. For masses in the GeV-TeV range, the simplest model with three flavors, leads to signals at future direct detection experiments like DARWIN. Interestingly, freeze-in with a smaller flavor group such as $SU(2)$ is already being probed by XENON1T.