Soft Gamma Rays from Heavy WIMPs

TL;DR

This paper proposes a supersymmetric WIMP model with heavy neutralinos explaining the galactic gamma ray excess through cascade decays, predicting observable signatures at the LHC.

Contribution

It introduces a novel heavy WIMP scenario with cascade decay mechanisms that produce a softer gamma ray spectrum, aligning with observations.

Findings

Gamma ray spectrum peaks at GeV energies due to cascade decays

Model predicts correlated diboson and dijet signatures at the LHC

Heavy neutralino WIMPs up to 500 GeV can explain the excess

Abstract

We propose an explanation of the galactic center gamma ray excess by supersymmetric WIMPs as heavy as 500 GeV. The lightest neutralino annihilates into vector-like leptons or quarks which cascade decay through intermediate Higgs bosons. Due to the long decay chains, the gamma ray spectrum is much softer than naively expected and peaks at GeV energies. The model predicts correlated diboson and dijet signatures to be tested at the LHC.