Search for the third-generation scalar leptoquarks and heavy right-handed neutrinos in $\tau_{\ell} \tau_{h}$jj final states in pp collisions at 13 TeV

A search is performed for the third-generation scalar leptoquarks and heavy right handed neutrinos in events containing one electron or muon, one hadronically decaying $\tau$ lepton, and at least two jets, using a $\sqrt{s}=13~\mathrm{TeV}$ pp collision data sample corresponding to $12.9~\mathrm{fb}^{-1}$ collected by the CMS detector at the LHC in 2016. The number of observed events is found to be in agreement with the standard model prediction in both search analyses. A $95\%$ CL limit is set on the product of the leptoquark pair production cross section and $\beta^2$, where $\beta$ is the branching fraction of the leptoquark decay to a $\tau$ lepton and a b quark. Assuming $\beta=1$, the third-generation leptoquarks with masses below $900~\mathrm{GeV}$ are excluded at $95\%$ CL. The right-handed neutrinos are searched in decays of right-handed $\mathrm{W}_{\mathrm{R}}$ bosons. The heavy right-handed neutrinos are excluded at $95\%$ CL for a range of neutrino masses below the $\mathrm{W}_{\mathrm{R}}$ mass, dependent on the value of $\mathrm{M_{W_{R}}}$. Assuming the mass of neutrino to be half of the mass of right-handed W boson, $\mathrm{W}_{\mathrm{R}}$ boson masses below $3.2~\mathrm{TeV}$ are excluded at $95\%$ CL.