  A search for top squark pair production in pp collisions at sqrt(s) = 13 TeV
is performed using events with a single isolated electron or muon, jets, and a
large transverse momentum imbalance. The results are based on data collected in
2016 with the CMS detector at the LHC, corresponding to an integrated
luminosity of 35.9 inverse femtobarns. No significant excess of events is
observed above the expectation from standard model processes. Exclusion limits
are set in the context of supersymmetric models of pair production of top
squarks that decay either to a top quark and a neutralino or to a bottom quark
and a chargino. Depending on the details of the model, we exclude top squarks
with masses as high as 1120 GeV. Detailed information is also provided to
facilitate theoretical interpretations in other scenarios of physics beyond the
standard model.
