On the importance of loop-induced spin-independent interactions for dark matter direct detection

TL;DR

This paper demonstrates that loop-induced spin-independent interactions can significantly enhance dark matter direct detection bounds, especially for tensor, pseudotensor, axialvector, and anapole interactions, challenging previous assumptions based solely on tree-level analyses.

Contribution

It reveals the importance of loop contributions in dark matter interactions, showing they can boost direct detection sensitivity for certain effective operators.

Findings

Loop effects induce spin-independent interactions in dark matter models.

Tensor and pseudotensor interactions generate magnetic and electric dipole moments at loop level.

Loop-induced couplings can surpass collider bounds for specific operators.

Abstract

The latest results from LHC searches for jets in association with missing transverse energy place strong bounds on the scattering cross section of dark matter. For the case of spin-dependent or momentum suppressed interactions these limits seem to be superior to the bounds from direct detection experiments. In this article, we show that loop contributions can significantly alter this conclusion and boost direct detection bounds, whenever they induce spin-independent interactions. This effect is most striking for tensor and pseudotensor interactions, which induce magnetic and electric dipole moments at loop level. For axialvector and anapole interactions a relevant contribution to direct detection signals arises from loop-induced Yukawa-like couplings between dark matter and quarks. We furthermore compare the resulting bounds to additional constraints on these effective operators arising from indirect searches and relic density requirements.