Impact of LHC data on muon g−2 solutions in a vectorlike extension of the constrained MSSM

Abstract

The long-standing discrepancy between the experimental determination by the Muon $g\ensuremath{-}2$ Collaboration at Brookhaven and the Standard Model predictions for the anomalous magnetic moment of the muon cannot be explained within a simple unified framework like the constrained minimal supersymmetric standard model, but it can within its extension with vectorlike fermions. In this paper we consider a model with an additional vectorlike $5+\overline{5}$ 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 the electroweak sparticle search at the LHC based on a 13 TeV search with $36.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity. We show that null trilepton signal searches coming from chargino-neutralino pair production significantly constrain 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 $g\ensuremath{-}2$ experiment at Fermilab with its projected sensitivity reach of $7\ensuremath{\sigma}$ 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.