Searches for additional Higgs bosons and for vector leptoquarks in ττ final states in proton-proton collisions at $ \sqrt{s} $ = 13 TeV

Three searches are presented for signatures of physics beyond the standard model (SM) in ττ final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at $\sqrt{s} = 13 TeV$, corresponding to an integrated luminosity of 138 fb$^{−1}$. Upper limits at 95% confidence level (CL) are set on the products of the branching fraction for the decay into $τ$ leptons and the cross sections for the production of a new boson $ϕ$, in addition to the H(125) boson, via gluon fusion $(ggϕ)$ or in association with b quarks, ranging from $O(10 pb)$ for a mass of $60 GeV$ to 0.3 fb for a mass of $3.5 TeV$ each. The data reveal two excesses for $ggϕ$ production with local $p$-values equivalent to about three standard deviations at $mϕ = 0.1$ and $1.2 TeV$. In a search for $t$-channel exchange of a vector leptoquark $U_1$, 95% CL upper limits are set on the dimensionless $U_1$ leptoquark coupling to quarks and $τ$ leptons ranging from 1 for a mass of $1 TeV$ to 6 for a mass of $5 TeV$, depending on the scenario. In the interpretations of the $M^{125}_h$ and $M^{125}_{h,EFT}$ minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below $350 GeV$ are excluded at 95% CL.