New probes for bino dark matter with coannihilation at the LHC

TL;DR

This paper explores how long-lived gluinos and winos, resulting from bino dark matter coannihilation scenarios, can be effectively tested at the LHC using displaced vertex searches, providing a novel probe for supersymmetric dark matter.

Contribution

It introduces a new approach to detect bino dark matter coannihilation scenarios through long-lived particle signatures at the LHC.

Findings

Long-lived gluinos and winos can be detected via displaced vertices at the LHC.

Displaced vertex searches significantly improve sensitivity to these scenarios.

The proposed method offers a promising way to test supersymmetric dark matter models.

Abstract

It has been widely known that bino-like dark matter in supersymmetric theories suffers from over-production. The situation can be improved if the gluino or wino has a mass of O(10) GeV heavier than the bino, sufficiently reducing the bino abundance through co-annihilation. In this scenario, the gluino decays to the bino via squark exchange, and the wino decays to the bino via higgsino exchange. In split SUSY models favoured after the Higgs discovery, the intermediate particles in these decays would be much heavier than gauginos, suppressing the decay of the gluino and wino. This, in addition to the small mass differences, results in long lifetimes for the gluino and wino. We show that searches performed at the LHC for long-lived particles with displaced vertices offer a powerful method to test this scenario.