Angular cuts to reduce the tautaubar+jet background to the higgsino signal at the LHC

TL;DR

This paper proposes angular cuts to effectively suppress background events in higgsino searches at the LHC, improving detection prospects by analyzing specific decay channels and background reduction techniques.

Contribution

It introduces a novel angular cut method to better reduce Z to tau tau background in higgsino searches at the LHC, surpassing previous methods.

Findings

Angular cuts outperform m_{ττ}^2<0 cut in background suppression.

The analysis estimates LHC14 reach for 300 and 3000 fb^{-1}.

Dilepton mass distribution helps characterize the higgsino signal.

Abstract

We re-examine higgsino pair production in association with a hard QCD jet at the LHC. We focus on \ell^+\ell^- +MET +jet events from the production and subsequent decay, \tchi_2^0\to\tchi_1^0\ell^+\ell^-, of the heavier neutral higgsino. The novel feature of our analysis is that we propose angular cuts to reduce the irreducible background from Z(-> \tau\bar{\tau})+jet events more efficiently than the m_{\tau\tau}^2<0 cut that has been used by the ATLAS and CMS collaborations. Additional cuts, needed to reduce backgrounds from t\bar{t}, WWj and W/Z+\ell\bar{\ell} production, are also delineated. We evaluate the reach of LHC14 for 300 and 3000~fb^{-1} and stress that the dilepton mass distribution would serve to characterize the higgsino signal.