Constraints on anomalous H V V couplings from the production of Higgs bosons decaying to τ lepton pairs

Abstract

A study is presented of anomalous H V V interactions of the Higgs boson, including its C P properties. The study uses Higgs boson candidates produced mainly in vector boson fusion and gluon fusion that subsequently decay to a pair of τ leptons. The data were recorded by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 35.9 fb − 1 . A matrix element technique is employed for the analysis of anomalous interactions. The results are combined with those from the H → 4 ℓ decay channel presented earlier, yielding the most stringent constraints on anomalous Higgs boson couplings to electroweak vector bosons expressed as effective cross section fractions and phases: the C P -violating parameter f a 3 cos ( ϕ a 3 ) = ( 0.00 ± 0.27 ) × 10 − 3 and the C P -conserving parameters f a 2 cos ( ϕ a 2 ) = ( 0.0 8 + 1.04 − 0.21 ) × 10 − 3 , f Λ 1 cos ( ϕ Λ 1 ) = ( 0.0 0 + 0.53 − 0.09 ) × 10 − 3 , and f Z γ Λ 1 cos ( ϕ Z γ Λ 1 ) = ( 0. 0 + 1.1 − 1.3 ) × 10 − 3 . The current dataset does not allow for precise constraints on C P properties in the gluon fusion process. The results are consistent with standard model expectations.