Light higgsino scenario confronted with muon g-2

TL;DR

This paper investigates the light higgsino scenario in supersymmetry, analyzing its compatibility with muon g-2 data and dark matter constraints, and assesses detection prospects at future experiments like LZ and HL-LHC.

Contribution

It provides a detailed parameter space analysis of the light higgsino scenario considering muon g-2 and dark matter constraints, including future detection prospects.

Findings

Winos and sleptons are constrained to be below 3 TeV and 800 GeV respectively for muon g-2 explanation.

Light higgsino-like dark matter can be detected by future LZ dark matter experiments.

HL-LHC can probe additional regions of the parameter space for light sleptons.

Abstract

Light higgsinos below several hundred GeV are favored or required by the naturalness of low energy supersymmetry. If only higgsinos are light while other sparticles are sufficiently heavy, we have the so-called light higgsino scenario. Confronted with the muon $g-2$ data, this scenario is examined in this work. Since in this scenario the LSP (lightest sparticle) is higgsino-like, we need to also consider the dark matter constraints. Assuming a light higgsino mass parameter $\mu$ in the range of 100-400 GeV while gaugino mass parameters above TeV, we explore the parameter space under the muon $g-2$ data and the dark matter constraints. We find that, to explain the muon $g-2$ anomaly at $2\sigma$, the winos and sleptons are respectively upper bounded by 3 TeV and 800 GeV. In this case, we find that the light higgsino-like dark matter can sizably scatter with nucleon and thus the allowed parameter space can be covered almost fully by the future LZ dark matter detection project. We also perform a Monte Carlo simulation to figure out the potential of HL-LHC to detect the light sleptons in this scenario. It turns out that compared with the current LHC limits, the HL-LHC can further cover a part of the parameter space.