Constraints on models of scalar and vector leptoquarks decaying to a quark and a neutrino at $\sqrt{s}=13~\mathrm{TeV}$

Many searches for Supersymmetry at the CERN LHC are sensitive to other scenarios of physics beyond the standard model. In this note, the results of a previous search for squarks and gluinos are re-interpreted to constrain models of leptoquark production. Pair production is considered, and both leptoquarks are assumed to decay to a quark and a neutrino. The search selects jets in association with a transverse momentum imbalance, using the $M_{\mathrm{T2}}$ variable. The analysis uses proton-proton collision data at $\sqrt{s}=13~\mathrm{TeV}$, recorded with the CMS detector at the LHC in 2016 and corresponding to an integrated luminosity of $35.9~\mathrm{fb}^{-1}$. Compared to previous CMS results, both scalar and vector leptoquarks are considered, as well as higher leptoquark mass values, and for the first time, leptoquark decays to a light quark (any single one of u, d, s, or c) and a neutrino are considered. Assuming scalar (vector) leptoquarks decaying with unity branching fraction to a light quark and neutrino, masses below $980~(1790)~\mathrm{GeV}$ are excluded by the observed data. For leptoquarks decaying to a bottom quark and a neutrino, masses below $1100~(1810)~\mathrm{GeV}$ are excluded, while assuming decays to a top quark and a neutrino, masses below $1020~(1780)~\mathrm{GeV}$ are excluded. Vector leptoquarks decaying with a $50\%$ branching fraction to a top quark and a neutrino, and $50\%$ to a bottom quark and tau lepton, have been proposed as an explanation of anomalous flavor physics results. In such a model, we exclude leptoquarks with masses below $1530~\mathrm{GeV}$, placing the most stringent constraint to date.