Searches for additional Higgs bosons and for vector leptoquarks in ττ final states in proton-proton collisions at √s=13 TeV

Three searches are presented for signatures of physics beyond the standard model (SM) in tau tau final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at root 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 tau leptons and the cross sections for the production of a new boson phi, in addition to the H(125) boson, via gluon fusion (gg phi) 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 3.5TeV each. The data reveal two excesses for gg phi production with local p-values equivalent to about three standard deviations at m(phi) = 0.1 and 1.2TeV. In a search for t-channel exchange of a vector leptoquark U-1, 95% CL upper limits are set on the dimensionless U1 leptoquark coupling to quarks and tau leptons ranging from 1 for a mass of 1TeV to 6 for a mass of 5TeV, depending on the scenario. In the interpretations of the M-h(125) and M-h,EFT(125) minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below 350 GeV are excluded at 95% CL.

Automated summary

Three searches were conducted for physics beyond the standard model in tau tau final states in proton-proton collisions at the LHC. Upper limits were set on the products of branching fraction for decay into tau leptons and cross sections for production of new boson φ, revealing excesses for gg φ production at certain masses. Limits were also set on the dimensionless U1 leptoquark coupling in the search for t-channel exchange of a vector leptoquark U-1. Additional Higgs bosons with masses below 350 GeV were excluded in interpretations of minimal supersymmetric SM benchmark scenarios.