A search for new phenomena in pp collisions at sqrt(s) = 13 TeV in final states with missing transverse momentum and at least one jet using the alphaT variable

TL;DR

This paper reports a search for new physics in proton-proton collisions at 13 TeV using the CMS detector, focusing on events with jets and missing transverse momentum, setting limits on supersymmetric particle masses.

Contribution

It introduces a search strategy using the alphaT variable to discriminate standard model backgrounds and interprets results within simplified supersymmetric models.

Findings

No excess over standard model expectations observed.

Gluino masses up to 1575 GeV excluded.

Top squark masses up to 400 GeV excluded.

Abstract

A search for new phenomena is performed in final states containing one or more jets and an imbalance in transverse momentum in pp collisions at a centre-of-mass energy of 13 TeV. The analysed data sample, recorded with the CMS detector at the CERN LHC, corresponds to an integrated luminosity of 2.3 inverse femtobarns. Several kinematic variables are employed to suppress the dominant background, multijet production, as well as to discriminate between other standard model and new physics processes. The search provides sensitivity to a broad range of new-physics models that yield a stable weakly interacting massive particle. The number of observed candidate events is found to agree with the expected contributions from standard model processes, and the result is interpreted in the mass parameter space of fourteen simplified supersymmetric models that assume the pair production of gluinos or squarks and a range of decay modes. For models that assume gluino pair production, masses up to 1575 and 975 GeV are excluded for gluinos and neutralinos, respectively. For models involving the pair production of top squarks and compressed mass spectra, top squark masses up to 400 GeV are excluded.