Abstract
A search is presented for supersymmetric partners of the top quark (top
squarks) in final states with two oppositely charged leptons (electrons
or muons), jets identified as originating from bquarks, and missing
transverse momentum. The search uses data from proton-proton collisions
at root s = 13 TeV collected with the CMS detector, corresponding to an
integrated luminosity of 137 fb(-1). Hypothetical signal events are
efficiently separated from the dominant top quark pair production
background with requirements on the significance of the missing
transverse momentum and on transverse mass variables. No significant
deviation is observed from the expected background. Exclusion limits are
set in the context of simplified supersymmetric models with
pair-produced lightest top squarks. For top squarks decaying exclusively
to a top quark and a lightest neutralino, lower limits are placed at
95% confidence level on the masses of the top squark and the neutralino
up to 925 and 450 GeV, respectively. If the decay proceeds via an
intermediate chargino, the corresponding lower limits on the mass of the
lightest top squark are set up to 850 GeV for neutralino masses below
420 GeV. For top squarks undergoing a cascade decay through charginos
and sleptons, the mass limits reach up to 1.4 TeV and 900 GeV
respectively for the top squark and the lightest neutralino.