Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper combines multiple CMS searches at 13 TeV to set new limits on top squark and neutralino masses, significantly extending the exclusion regions for supersymmetric top quark partners and exploring dark matter models.

Contribution

It presents the first combined analysis of CMS data for top squark searches, improving sensitivity and exclusion limits across various parameter spaces.

Findings

Excluded top squark masses up to 1325 GeV for a massless neutralino

Excluded neutralino masses up to 700 GeV for a top squark mass of 1150 GeV

First CMS exclusion of top squarks with masses 145-295 GeV in specific decay scenarios

Abstract

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb$^{-1}$ collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on the model, the combined result excludes a top squark mass up to 1325 GeV for a massless neutralino, and a neutralino mass up to 700 GeV for a top squark mass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV.