Electroweakly-Interacting Dirac Dark Matter

TL;DR

This paper investigates fermionic dark matter candidates with electroweak interactions, analyzing experimental constraints and future detection prospects, focusing on hypercharge values and their implications for dark matter models.

Contribution

It evaluates the experimental constraints on electroweakly-interacting Dirac dark matter with various hypercharges using an effective field approach, providing insights into viable parameter spaces.

Findings

Constraints restrict hypercharge Y≥3/2 dark matter candidates.

Future experiments can probe or disfavor Y≥1 cases.

Y=0 and 1/2 remain viable for SU(2)_L charged fermionic dark matter.

Abstract

We consider a class of fermionic dark matter candidates that are charged under both the SU(2)$_L$ and U(1)$_Y$ gauge interactions. In this case a certain amount of dark matter-Higgs couplings, which can split the dark matter into a pair of Majorana fermions, should be present to evade the constraints from the dark matter direct detection experiments. These effects may be probed by means of the dark matter-nucleus scattering via the Higgs-boson exchange process, as well as the electric dipole moments induced by the dark matter and its SU(2)$_L$ partner fields. In this article, we evaluate them with an effective field approach. It turns out that the constraints coming from the experiments for the quantities have already restricted the dark matter with hypercharge $Y\geq 3/2$. Future experiments have sensitivities to probe this class of dark matter candidates, and may disfavor the $Y\geq 1$ cases if no signal is observed. In this case, only the $Y=0$ and $1/2$ cases may be the remaining possibilities for the SU(2)$_L$ charged fermionic dark matter candidates.