Bottom quark contribution to spin-dependent dark matter detection

TL;DR

This paper explores the significant role of bottom quark contributions in spin-dependent dark matter detection within the MSSM, highlighting their impact on cross sections and experimental constraints.

Contribution

It identifies and analyzes the previously overlooked bottom quark contribution to spin-dependent DM scattering, especially in MSSM scenarios with gaugino or Higgsino dominance.

Findings

Bottom quark contribution can be substantial in certain parameter regions.

The contribution remains consistent with existing spin-independent constraints.

A viable parameter space exists where bottom quark effects are important.

Abstract

We investigate a previously overlooked bottom quark contribution to the spin-dependent cross section for Dark Matter(DM) scattering from the nucleon. While the mechanism is relevant to any supersymmetric extension of the Standard Model, for illustrative purposes we explore the consequences within the framework of the Minimal Supersymmetric Standard Model(MSSM). We study two cases, namely those where the DM is predominantly Gaugino or Higgsino. In both cases, there is a substantial, viable region in parameter space ($m_{\tilde{b}} - m_\chi \lesssim \mathcal{O}(100)$ GeV) in which the bottom contribution becomes important. We show that a relatively large contribution from the bottom quark is consistent with constraints from spin-independent DM searches, as well as some incidental model dependent constraints.