  Search results are presented for physics beyond the standard model in final
states with two opposite-charge, same-flavor leptons, jets, and missing
transverse momentum. The data sample corresponds to an integrated luminosity of
35.9 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} = $ 13 TeV collected
with the CMS detector at the LHC in 2016. The analysis uses the invariant mass
of the lepton pair, searching for a kinematic edge or a resonant-like excess
compatible with the Z boson mass. The search for a kinematic edge targets
production of particles sensitive to the strong force, while the resonance
search targets both strongly and electroweakly produced new physics. The
observed yields are consistent with the expectations from the standard model,
and the results are interpreted in the context of simplified models of
supersymmetry. In a gauge mediated supersymmetry breaking (GMSB) model of
gluino pair production with decay chains including Z bosons, gluino masses up
to 1500-1770 GeV are excluded at the 95% confidence level depending on the
lightest neutralino mass. In a model of electroweak chargino-neutralino
production, chargino masses as high as 610 GeV are excluded when the lightest
neutralino is massless. In GMSB models of electroweak neutralino-neutralino
production, neutralino masses up to 500-650 GeV are excluded depending on the
decay mode assumed. Finally, in a model with bottom squark pair production and
decay chains resulting in a kinematic edge in the dilepton invariant mass
distribution, bottom squark masses up to 980-1200 GeV are excluded depending on
the mass of the next-to-lightest neutralino.
