Heavy Bino Dark Matter and Collider Signals in the MSSM with Vector-like 4th-Generation Particles

TL;DR

This paper explores MSSM4G models with vector-like particles, highlighting their potential for heavy Bino dark matter detection and collider signals, with implications for future experiments like CTA and LHC.

Contribution

It introduces the MSSM4G models QUE and QDEE, demonstrating their ability to naturally accommodate heavy Bino dark matter and predicting specific collider and detection signatures.

Findings

Heavy Bino dark matter (300-700 GeV) is viable in these models.

Next-generation experiments can detect dark matter signals above neutrino background.

LHC discovery prospects depend on the mass and decay modes of 4th-generation leptons.

Abstract

MSSM4G models, in which the minimal supersymmetric standard model is extended to include vector-like copies of standard model particles, are promising possibilities for weak-scale supersymmetry. In particular, two models, called QUE and QDEE, realize the major virtues of supersymmetry (naturalness consistent with the 125 GeV Higgs boson, gauge coupling unification, and thermal relic neutralino dark matter) without the need for fine-tuned relations between particle masses. We determine the implications of these models for dark matter and collider searches. The QUE and QDEE models revive the possibility of heavy Bino dark matter with mass in the range 300-700 GeV, which is not usually considered. Dark matter direct detection cross sections are typically below current limits, but are naturally expected above the neutrino floor and may be seen at next-generation experiments. Indirect detection prospects are bright at the Cherenkov Telescope Array, provided the 4th-generation leptons have mass above 350 GeV or decay to taus. In a completely complementary way, discovery prospects at the LHC are dim if the 4th-generation leptons are heavy or decay to taus, but are bright for 4th-generation leptons with masses below 350 GeV that decay either to electrons or to muons. We conclude that the combined set of direct detection, CTA, and LHC experiments will discover or exclude these MSSM4G models in the coming few years, assuming the Milky Way has an Einasto dark matter profile.