Impact of LHC data on muon $g-2$ solutions in vector-like extension of the Constrained MSSM

TL;DR

This paper explores how adding vector-like fermions to the Constrained MSSM can explain the muon g-2 discrepancy, analyzing parameter space constraints from LHC searches and future Fermilab measurements.

Contribution

It demonstrates that vector-like extensions can reconcile muon g-2 data with collider constraints, highlighting the impact of upcoming experiments on the model's viability.

Findings

Allowed chargino mass range: 700-1200 GeV

LHC trilepton searches constrain parameter space

Future Fermilab g-2 results could challenge the model

Abstract

The long-standing discrepancy between the experimental determination by the Muon $g-2$ Collaboration at Brookhaven and the Standard Model predictions for the anomalous magnetic moment of the muon cannot be explained within simple unified framework like the Constrained Minimal Supersymmetric Standard Model, but it can within its extension with vector-like fermions. In this paper we consider a model with an additional vector-like $5+\bar{5}$ pair of $SU(5)$. Within this model we first identify its parameter space that is consistent with the current discrepancy and show that this implies the lighter chargino mass in the range of $700-1200$ GeV. We examine how it is affected by constraints from electroweak sparticle search at the LHC based on 13 TeV search with 36.1 ${fb}^{-1}$ integrated luminosity. We show that null trilepton signal searches coming from chargino-neutralino pair production significantly constrains the allowed parameter space except when the chargino-neutralino mass difference is relatively small, below about 10 GeV. Next we consider the expected impact of the New Muon $g-2$ experiment at Fermilab with its projected sensitivity reach of $7\,\sigma$ and, assuming it confirms the current discrepancy, show that the remaining parameter space of the considered model will be in strong tension with the current LHC limits.