Search for top squark pair production in a final state with two tau leptons in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper reports a search for top squark pair production in proton-proton collisions at 13 TeV, focusing on final states with two tau leptons and missing energy, setting exclusion limits up to 1100 GeV for the top squark.

Contribution

It presents the first search targeting top squark decays to tau leptons in this specific final state at 13 TeV, providing new exclusion limits within simplified supersymmetric models.

Findings

No significant excess over background observed.

Top squark masses up to 1100 GeV excluded for nearly massless neutralino.

Results constrain supersymmetric models with tau-rich decay channels.

Abstract

A search for pair production of the supersymmetric partner of the top quark, the top squark, in proton-proton collision events at $\sqrt{s} =$ 13 TeV is presented in a final state containing hadronically decaying tau leptons and large missing transverse momentum. This final state is highly sensitive to high-$\tan{\beta}$ or higgsino-like scenarios in which decays of electroweak gauginos to tau leptons are dominant. The search uses a data set corresponding to an integrated luminosity of 77.2 fb$^{-1}$, which was recorded with the CMS detector during 2016 and 2017. No significant excess is observed with respect to the background prediction. Exclusion limits at 95% confidence level are presented in the top squark and lightest neutralino mass plane within the framework of simplified models, in which top squark masses up to 1100 GeV are excluded for a nearly massless neutralino.