Direct Detection of Electroweak-Interacting Dark Matter

TL;DR

This paper calculates the elastic scattering cross section of electroweak-interacting dark matter with nucleons, revealing a significant cancellation that results in a cross section far below current detection limits.

Contribution

It provides the first comprehensive leading-order calculation of the dark matter-nucleon scattering cross section including two-loop processes and identifies an accidental cancellation effect.

Findings

Cross section is approximately 10^(-46 to -48) cm^2.

Cancellation among quantum contributions suppresses the cross section.

Results are well below current experimental bounds.

Abstract

Assuming that the lightest neutral component in an SU(2)L gauge multiplet is the main ingredient of dark matter in the universe, we calculate the elastic scattering cross section of the dark matter with nucleon, which is an important quantity for the direct detection experiments. When the dark matter is a real scalar or a Majorana fermion which has only electroweak gauge interactions, the scattering with quarks and gluon are induced through one- and two-loop quantum processes, respectively, and both of them give rise to comparable contributions to the elastic scattering cross section. We evaluate all of the contributions at the leading order and find that there is an accidental cancellation among them. As a result, the spin-independent cross section is found to be O(10^-(46-48)) cm^2, which is far below the current experimental bounds.