François Englert (1932 – 2026) – Home | CERN

Constraints on anomalous Higgs boson couplings to vector bosons and fermions using the $γγ$ final state in proton-proton collisions at $\sqrt{s}$ = 13 TeV

Possible anomalous couplings of the Higgs boson to vector bosons and fermions are studied using Higgs boson candidates decaying to a pair of photons. The study is based on proton-proton collision data at $\sqrt{s}$ = 13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb$^{-1}$. Events with Higgs boson candidates produced via gluon fusion, electroweak vector boson fusion and in association with a vector boson, are categorized using matrix element techniques and multivariate discriminants. The $CP$ properties of the Higgs boson couplings to gluons through loops of heavy particles, as well as the tensor structure of its interactions with two electroweak bosons, are investigated. The results are interpreted in terms of the fractional contributions of anomalous Higgs boson couplings to the total production cross section of each process and are found to be consistent with the standard model expectations.

Constraints on anomalous Higgs boson couplings to vector bosons and fermions using the $ \gamma\gamma $ final state in proton-proton collisions at $ \sqrt{s} = $ 13 TeV

Possible anomalous couplings of the Higgs boson to vector bosons and fermions are studied using Higgs boson candidates decaying to a pair of photons. The study is based on proton-proton collision data at $ \sqrt{s} = $ 13 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb$ ^{-1} $. Events with Higgs boson candidates produced via gluon fusion, electroweak vector boson fusion and in association with a vector boson, are categorized using matrix element techniques and multivariate discriminants. The $ CP $ properties of the Higgs boson couplings to gluons through loops of heavy particles, as well as the tensor structure of its interactions with two electroweak bosons, are investigated. The results are interpreted in terms of the fractional contributions of anomalous Higgs boson couplings to the total production cross section of each process and are found to be consistent with the standard model expectations.

Improved results on Higgs boson pair production in the 4b final state

Measurements of Higgs boson pair (HH) production in the four bottom quark (4b) final state are presented using proton-proton (pp) collision data at $\sqrt{s}$ = 13.6 TeV collected by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 62 fb$^{-1}$. Events in which the Higgs boson decays, H$\mathrm{t\bar{t}}$, are separately reconstructed as pairs of small-radius jets (resolved), as well as those where they are reconstructed as single large-radius jets (merged), are studied exclusively. Benefiting from new methods in trigger selection, event selection, and signal extraction, the combination of analyses in the resolved and merged topologies gives an observed (expected) upper limit on the HH signal strength, $μ_\mathrm{HH}$, of 4.4 (4.4) at 95% confidence level (CL). Compared to previously published LHC results in the 4b final state, the expected limit with an equivalent integrated luminosity is improved by more than a factor of two in the resolved topology and is better in the merged topology as well. An updated analysis of the resolved topology using 138 fb$^{-1}$ of 13 TeV pp collision data yields an observed (expected) 95% CL upper limit on $μ_\mathrm{HH}$ of 10.0 (5.9), an improvement of about 25% in the expected limit compared to the published results using the same data. Results in the 4b final state with 13 and 13.6 TeV are combined, resulting in an observed (expected) 95% CL upper limit on $μ_\mathrm{HH}$ of 4.7 (2.8). The allowed ranges for the Higgs boson trilinear self-coupling and quartic coupling between two Higgs bosons and two vector bosons are also reported. These are the most stringent constraints achieved in the 4b final state to date.

Improved results on Higgs boson pair production in the 4b final state

Measurements of Higgs boson pair (HH) production in the four bottom quark (4b) final state are presented using proton-proton (pp) collision data at $ \sqrt{s}= $ 13.6 TeV collected by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 62 fb$ ^{-1} $. Events in which the Higgs boson decays, $ \mathrm{H} \to \mathrm{b}\overline{\mathrm{b}} $, are separately reconstructed as pairs of small-radius jets (resolved), as well as those where they are reconstructed as single large-radius jets (merged), are studied exclusively. Benefiting from new methods in trigger selection, event selection, and signal extraction, the combination of analyses in the resolved and merged topologies gives an observed (expected) upper limit on the HH signal strength, $ \mu_{\mathrm{H}\mathrm{H}} $, of 4.4 (4.4) at 95\% confidence level (CL). Compared to previously published LHC results in the 4b final state, the expected limit with an equivalent integrated luminosity is improved by more than a factor of two in the resolved topology and is better in the merged topology as well. An updated analysis of the resolved topology using 138 fb$ ^{-1} $ of 13 TeV pp collision data yields an observed (expected) 95% CL upper limit on $ \mu_{\mathrm{H}\mathrm{H}} $ of 10.0 (5.9), an improvement of about 25% in the expected limit compared to the published results using the same data. Results in the 4b final state with 13 and 13.6 TeV are combined, resulting in an observed (expected) 95% CL upper limit on $ \mu_{\mathrm{H}\mathrm{H}} $ of 4.7 (2.8). The allowed ranges for the Higgs boson trilinear self-coupling and quartic coupling between two Higgs bosons and two vector bosons are also reported. These are the most stringent constraints achieved in the 4b final state to date.

Search for associated production of a Higgs boson and two vector bosons via vector boson scattering at $ \sqrt{s} = $ 13 TeV

A search for Higgs boson (H) production in association with two vector bosons ($ \mathrm{V} = \mathrm{W} $, Z) via vector boson scattering (VBS) is presented using proton-proton collision data collected at $ \sqrt{s}= $ 13 TeV by the CMS experiment, corresponding to an integrated luminosity of 138 fb$ ^{-1} $. Events containing two forward jets consistent with VBS, a large-radius jet from the decay of a boosted H to a pair of b quarks, and 0, 1, or 2 charged leptons coming from V decays are selected. The process is excluded at 95% CL for observed (expected) values of the $ \mathrm{V}\mathrm{V}\mathrm{H}\mathrm{H} $ coupling modifier $ \kappa_{2\mathrm{V}} $ outside the interval 0.40 $ < \kappa_{2\mathrm{V}} < $ 1.60 (0.34 $ < \kappa_{2\mathrm{V}} < $ 1.66), assuming standard model values for all other couplings, thus establishing a novel probe of the $ \mathrm{V}\mathrm{V}\mathrm{H}\mathrm{H} $ interaction. Constraints are also set on the individual $ \kappa_{2\mathrm{W}} $ and $ \kappa_{2\mathrm{Z}} $ coupling modifiers, and on the allowed region in the $ \kappa_{2\mathrm{W}}-\kappa_{2\mathrm{Z}} $ plane.