Constraints on Light Dark Matter from Single-Photon Decays of Heavy Quarkonium

TL;DR

This paper explores how heavy quarkonium decays into dark matter and a photon can set constraints on light dark matter interactions, complementing other detection methods and extending sensitivity to challenging mass ranges.

Contribution

It provides the first comprehensive analysis of quarkonium decay constraints on light dark matter interactions using effective contact operators.

Findings

Limits on the branching fraction of $1S$ decays to dark matter and photon.

Constraints on interaction strength for dimension 6 or lower operators.

Inferred limits on dark matter-nucleon scattering cross sections.

Abstract

We investigate constraints on the interactions of light dark matter with Standard Model quarks in a framework with effective contact operators mediating the decay of heavy flavor bound state quarkonium to dark matter and a photon. When considered in combination with decays to purely invisible final states, constraints from heavy quarkonium decays at high intensity electron-positron colliders can complement missing energy searches at high energy colliders and provide sensitivity to dark matter masses difficult to probe at direct and indirect detection experiments. We calculate the approximate limits on the branching fraction for $\Upsilon (1 S)$ decays to dark matter and a photon. Given the approximate limits on the branching fractions for all dimension 6 or lower contact operators, we present the corresponding limits on the interaction strength for each operator and the inferred limits on dark matter-nucleon scattering. Complementary constraints on dark matter annihilation from gamma-ray searches from dwarf spheroidal galaxies are also considered.