Model-independent analysis of the DAMPE excess

TL;DR

This paper explores various dark matter models that could explain the DAMPE excess at 1.4 TeV, identifying viable scenarios that evade current experimental constraints and delineating the parameter space for mediators.

Contribution

It provides a comprehensive, model-independent analysis of dark matter interactions that could produce the DAMPE excess, considering all renormalizable couplings and constraints.

Findings

Half of the models are ruled out by suppression effects.

Remaining models evade current experimental constraints.

Mediator masses must be above 2 TeV according to LEP limits.

Abstract

The Dark Matter Particle Explorer (DAMPE) recently released measurements of the electron spectrum with a hint of a narrow peak at about 1.4 TeV. We investigate dark matter (DM) models that could produce such a signal by annihilation in a nearby subhalo whilst simultaneously satisfying constraints from DM searches. In our model-independent approach, we consider all renormalizable interactions via a spin 0 or 1 mediator between spin 0 or 1/2 DM particles and the Standard Model leptons. We find that of the 20 combinations, 10 are ruled out by velocity or helicity suppression of the annihilation cross section to fermions. The remaining 10 models, though, evade constraints from the relic density, collider and direct detection searches, and include models of spin 0 and 1/2 DM coupling to a spin 0 or 1 mediator. We delineate the regions of mediator mass and couplings that could explain the DAMPE excess. In all cases the mediator is required to be heaver than about 2 TeV by LEP limits.