Search for anomalous triple gauge couplings in WW and WZ production in lepton + jet events in proton-proton collisions at s \sqrt{s} = 13 TeV

A search is presented for three additional operators that would lead to anomalous WWγ or WWZ couplings with respect to those in the standard model. They are constrained by studying events with two vector bosons; a W boson decaying to eν or μν, and a W or Z boson decaying hadronically, reconstructed as a single, massive, large- radius jet. The search uses a data set of proton-proton collisions at a centre-of-mass energy of 13 TeV, recorded by the CMS experiment at the CERN LHC in 2016, and corresponding to an integrated luminosity of 35.9 fb$^{-1}$. Using the reconstructed diboson invariant mass, 95% confidence intervals are obtained for the anomalous coupling parameters of −1.58 < cWWW/Λ2< 1.59 TeV−2, −2.00 < cW/Λ$^{2}$< 2.65 TeV$^{-2}$, and −8.78 < cB/Λ$^{2}$< 8.54 TeV$^{-2}$, in agreement with standard model expectations of zero for each parameter. These are the strictest bounds on these parameters to date

Search for direct pair production of supersymmetric partners to the τ lepton in proton–proton collisions at s=13 TeV\sqrt{s}=13\,\text {TeV}

A search is presented for τ slepton pairs produced in proton–proton collisions at a center-of-mass energy of 13 TeV. The search is carried out in events containing two τ leptons in the final state, on the assumption that each τ slepton decays primarily to a τ lepton and a neutralino. Events are considered in which each τ lepton decays to one or more hadrons and a neutrino, or in which one of the τ leptons decays instead to an electron or a muon and two neutrinos. The data, collected with the CMS detector in 2016 and 2017, correspond to an integrated luminosity of 77.2 fb$^{-1}$. The observed data are consistent with the standard model background expectation. The results are used to set 95% confidence level upper limits on the cross section for τ slepton pair production in various models for τ slepton masses between 90 and 200 GeV and neutralino masses of 1, 10, and 20 GeV. In the case of purely left-handed τ slepton production and decay to a τ lepton and a neutralino with a mass of 1GeV, the strongest limit is obtained for a τ slepton mass of 125 GeV at a factor of 1.14 larger than the theoretical cross section