A Froggatt-Nielsen Model for Leptophilic Scalar Dark Matter Decay

TL;DR

This paper proposes a leptophilic scalar dark matter model at the TeV scale, explaining cosmic ray positron excesses via Planck-suppressed decays primarily into leptons, consistent with observational data.

Contribution

It introduces a Froggatt-Nielsen inspired symmetry framework that naturally yields a long-lived, leptophilic dark matter candidate with specific decay channels and lifetimes.

Findings

Reproduces observed positron flux and fraction.

Remains consistent with antiproton flux bounds.

Decays mainly into leptons with suppressed hadronic channels.

Abstract

We construct a model of decaying, TeV-scale scalar dark matter motivated by data from the PAMELA and Fermi-LAT experiments. By introducing an appropriate Abelian discrete symmetry and an intermediate scale of vector-like states that are responsible for generating lepton Yukawa couplings, we show that Planck-suppressed corrections may lead to decaying dark matter that is leptophilic and has the desired lifetime. The dark matter candidate decays primarily to lepton/anti-lepton pairs, and at a subleading rate to final states with a lepton, anti-lepton and standard model Higgs boson. We show that the model can reproduce the observed positron flux and positron fraction while remaining consistent with the bounds on the cosmic ray antiproton flux.