Closing in on Asymmetric Dark Matter I: Model independent limits for interactions with quarks

TL;DR

This paper provides model-independent limits on asymmetric dark matter interactions with quarks, showing that many models with certain mass ranges are excluded by current experiments, and emphasizes the importance of light mediators.

Contribution

It offers a comprehensive effective operator analysis of experimental constraints on ADM, highlighting the exclusion of models with heavy mediators in specific mass ranges and exploring light mediator effects.

Findings

Models with 1-100 GeV DM mass annihilating to quarks via heavy mediators are excluded.

Light mediator states significantly affect exclusion limits through resonance and threshold effects.

Experimental constraints strongly suggest the need for portal interactions involving light states.

Abstract

It is argued that experimental constraints on theories of asymmetric dark matter (ADM) almost certainly require that the DM be part of a richer hidden sector of interacting states of comparable mass or lighter. A general requisite of models of ADM is that the vast majority of the symmetric component of the DM number density must be removed in order to explain the observed relationship $\Omega_B\sim\Omega_{DM}$ via the DM asymmetry. Demanding the efficient annihilation of the symmetric component leads to a tension with experimental limits if the annihilation is directly to Standard Model (SM) degrees of freedom. A comprehensive effective operator analysis of the model independent constraints on ADM from direct detection experiments and LHC monojet searches is presented. Notably, the limits obtained essentially exclude models of ADM with mass 1GeV$\lesssim m_{DM} \lesssim$ 100GeV annihilating to SM quarks via heavy mediator states. This motivates the study of portal interactions between the dark and SM sectors mediated by light states. Resonances and threshold effects involving the new light states are shown to be important for determining the exclusion limits.