Measurements of the Higgs boson width and anomalous HVV couplings from on-shell and off-shell production in the four-lepton final state

Abstract

Studies of on-shell and off-shell Higgs boson production in the four-lepton final state are presented, using data from the CMS experiment at the LHC that correspond to an integrated luminosity of 80.2 fb −1 at a center-of-mass energy of 13 TeV. Joint constraints are set on the Higgs boson total width and parameters that express its anomalous couplings to two electroweak vector bosons. These results are combined with those obtained from the data collected at center-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.7 fb −1 , respectively. Kinematic information from the decay particles and the associated jets are combined using matrix element techniques to identify the production mechanism and to increase sensitivity to the Higgs boson couplings in both production and decay. The constraints on anomalous HVV couplings are found to be consistent with the standard model expectation in both the onshell and off-shell regions. Under the assumption of a coupling structure similar to that in the standard model, the Higgs boson width is constrained to be 3.2 þ2.8 −2.2 MeV while the expected constraint based on simulation is 4.1 þ5.0 −4.0 MeV. The constraints on the width remain similar with the inclusion of the tested anomalous HVV interactions.

The Higgs width in the SMEFT

“…For some related results see Refs. [6][7][8][9][10]. This fact is also relevant when considering successor machines for a future precision Higgs phenomenology program.…”

“…1 The SMEFT extends the SM with operators Q are the Wilson coefficients. In this work we use the non-redundant L (6) Warsaw basis [2]. This basis removed some residual redundancies (see also [3,4]) in the over-complete basis of Ref.…”

NNLO QCD + NLO EW with Matrix+OpenLoops: precise predictions for vector-boson pair production

“…In particular, due to the high sensitivity to anomalous trilinear couplings, differential measurements at high transverse momenta probe the gauge symmetry structure of EW interactions and provide an excellent chance to detect indirect effects of physics beyond the Standard Model (BSM). Diboson final states are widely studied also in the context of direct BSM searches and in Higgs-boson measurements, where they are non-trivial irreducible backgrounds, as, for example, in the H → W + W − and H → ZZ analyses [1][2][3][4][5][6][7][8]. The increasing level of precision of experimental measurements calls for continuous improvements in the theoretical description of diboson production at the LHC.…”

CP-violating Higgs-gauge boson couplings in $$H\nu \bar{\nu }$$ production at three energy stages of CLIC

“…The possibility of CP-violating couplings involving higher-dimensional interaction terms containing the Higgs and gauge boson pairs cannot be discarded in the investigation of new physics. Searches for CP-violating Higgs-gauge boson couplings to higher-dimensional operators were previously performed in many rewarding studies at experimental LHC data [8][9][10][11] and phenomenologically at LHC [12-21], at HE-LHC and HL-LHC [22][23][24], at future e + e − [25-39] and ep colliders [40].The precision measurements of the Higgs boson couplings with the other SM particles at the LHC and planned future colliders will give us detailed information about its true nature. Among the proposed future collider projects, the Compact Linear Collider (CLIC) is a mature option for a future linear electron-positron collider [41,42], which is currently under development as a possible large-scale installation at CERN.…”

“…The possibility of CP-violating couplings involving higher-dimensional interaction terms containing the Higgs and gauge boson pairs cannot be discarded in the investigation of new physics. Searches for CP-violating Higgs-gauge boson couplings to higher-dimensional operators were previously performed in many rewarding studies at experimental LHC data [8][9][10][11] and phenomenologically at LHC [12-21], at HE-LHC and HL-LHC [22][23][24], at future e + e − [25-39] and ep colliders [40].…”