Neutralino Dark Matter with Light Staus

TL;DR

This paper explores scenarios where light neutralinos and staus in supersymmetry can account for dark matter, highlighting testable predictions for direct detection and Higgs decay experiments.

Contribution

It provides a pedagogical review of light stau and neutralino scenarios, identifying two distinct models with specific experimental signatures.

Findings

Light staus can enable correct relic abundance for neutralinos around 100 GeV.

Two scenarios predict observable signals in direct detection and Higgs decay channels.

Electroweak superpartners are within reach of current collider searches.

Abstract

In spite of rapid experimental progress, windows for light superparticles remain. One possibility is a ~100 GeV tau slepton whose t-channel exchange can give the correct thermal relic abundance for a relatively light neutralino. We pedagogically review how this region arises and identify two distinct scenarios that will be tested soon on multiple fronts. In the first, the neutralino has a significant down-type higgsino fraction and relatively large rates at direct detection experiments are expected. In the second, there is large mixing between two relatively light staus, which could lead to a significant excess in the Higgs boson branching ratio to photons. In addition, electroweak superpartners are sufficiently light that direct searches should be effective.