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A study of the anomalous couplings of the Higgs boson to vector bosons, including$${\textit{CP}}$$$\mathrm{CP}$-violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton–proton collision data collected with the CMS detector at the CERN LHC during 2016–2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138$$\,\text {fb}^{-1}$$${\text{fb}}^{-1}$. The different-flavor dilepton$$({\textrm{e}} {{\upmu }})$$$\left(\text{e}\mu \right)$final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson. Kinematic information from associated jets is combined using matrix element techniques to increase the sensitivity to anomalous effects at the production vertex. A simultaneous measurement of four Higgs boson couplings to electroweak vector bosons is performed in the framework of a standard model effective field theory. All measurements are consistent with the expectations for the standard model Higgs boson and constraints are set on the fractional contribution of the anomalous couplings to the Higgs boson production cross section.

A measurement is presented of a ratio observable that provides a measure of the azimuthal correlations among jets with large transverse momentum$$p_{\textrm{T}}$$$p_{\text{T}}$. This observable is measured in multijet events over the range of$$p_{\textrm{T}} = 360$$$p_{\text{T}}=360$–$$3170\,\text {Ge}\hspace{-.08em}\text {V} $$$3170\text{Ge}\text{V}$based on data collected by the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13$$\,\text {Te}\hspace{-.08em}\text {V}$$$\text{Te}\text{V}$, corresponding to an integrated luminosity of 134$$\,\text {fb}^{-1}$$${\text{fb}}^{-1}$. The results are compared with predictions from Monte Carlo parton-shower event generator simulations, as well as with fixed-order perturbative quantum chromodynamics (pQCD) predictions at next-to-leading-order (NLO) accuracy obtained with different parton distribution functions (PDFs) and corrected for nonperturbative and electroweak effects. Data and theory agree within uncertainties. From the comparison of the measured observable with the pQCD prediction obtained with the NNPDF3.1 NLO PDFs, the strong coupling at the Z boson mass scale is$$\alpha _\textrm{S} (m_{{\textrm{Z}}}) =0.1177 \pm 0.0013\, \text {(exp)} _{-0.0073}^{+0.0116} \,\text {(theo)} = 0.1177_{-0.0074}^{+0.0117}$$${\alpha }_{\text{S}}\left(m_{\text{Z}}\right)=0.1177\pm 0.0013{\text{(exp)}}_{-0.0073}^{+0.0116}\text{(theo)}=0.{1177}_{-0.0074}^{+0.0117}$, where the total uncertainty is dominated by the scale dependence of the fixed-order predictions. A test of the running of$$\alpha _\textrm{S}$$${\alpha }_{\text{S}}$in the$$\,\text {Te}\hspace{-.08em}\text {V}$$$\text{Te}\text{V}$region shows no deviation from the expected NLO pQCD behaviour.

Energy correlators that describe energy-weighted distances between two or three particles in a hadronic jet are measured using an event sample of$\sqrt{s}=13\mathrm{TeV}$proton-proton collisions collected by the CMS experiment and corresponding to an integrated luminosity of$36.3{\mathrm{fb}}^{-1}$. The measured distributions are consistent with the trends in the simulation that reveal two key features of the strong interaction: confinement and asymptotic freedom. By comparing the ratio of the measured three- and two-particle energy correlator distributions with theoretical calculations that resum collinear emissions at approximate next-to-next-to-leading-logarithmic accuracy matched to a next-to-leading-order calculation, the strong coupling is determined at the$Z$boson mass:${\alpha }_S(m_Z)=0.1229_{-0.0050}^{+0.0040}$, the most precise${\alpha }_S(m_Z)$value obtained using jet substructure observables.

The first observation of the decay${\mathrm{\Xi }}_b^{-}\to \psi (2S){\mathrm{\Xi }}^{-}$and measurement of the branching ratio of${\mathrm{\Xi }}_b^{-}\to \psi (2S){\mathrm{\Xi }}^{-}$to${\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-}$are presented. The$J/\psi$and$\psi (2S)$mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at$\sqrt{s}=13\mathrm{TeV}$in 2016–2018, corresponding to an integrated luminosity of$140{\mathrm{fb}}^{-1}$. The branching fraction ratio is measured to be$\mathcal{B}({\mathrm{\Xi }}_b^{-}\to \psi (2S){\mathrm{\Xi }}^{-})/\mathcal{B}({\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-})=0.84_{-0.19}^{+0.21}(\mathrm{stat})\pm 0.10(\mathrm{syst})\pm 0.02(\mathcal{B})$, where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the${\mathrm{\Xi }}_b(5945{)}^0$baryon mass and natural width are also presented, using the${\mathrm{\Xi }}_b^{-}{\pi }^{+}$final state, where the${\mathrm{\Xi }}_b^{-}$baryon is reconstructed through the decays$J/\psi {\mathrm{\Xi }}^{-}$,$\psi (2S){\mathrm{\Xi }}^{-}$,$J/\psi \mathrm{\Lambda }{K}^{-}$, and$J/\psi {\mathrm{\Sigma }}^0{K}^{-}$. Finally, the fraction of${\mathrm{\Xi }}_b^{-}$baryons produced from${\mathrm{\Xi }}_b(5945{)}^0$decays is determined.

A search for$${\text {Z}{}{}} {\text {Z}{}{}} $$$\text{Z}\text{Z}$and$${\text {Z}{}{}} {\text {H}{}{}} $$$\text{Z}\text{H}$production in the$${\text {b}{}{}} {\bar{{\text {b}{}{}}}{}{}} {\text {b}{}{}} {\bar{{\text {b}{}{}}}{}{}} $$$\text{b}\overline{\text{b}}\text{b}\overline{\text{b}}$final state is presented, where H is the standard model (SM) Higgs boson. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosity of 133$$\,\text {fb}^{-1}$$${\text{fb}}^{-1}$collected at a center-of-mass energy of 13$$\,\text {Te}\hspace{-.08em}\text {V}$$$\text{Te}\text{V}$with the CMS detector at the CERN LHC. The analysis introduces several novel techniques for deriving and validating a multi-dimensional background model based on control samples in data. A multiclass multivariate classifier customized for the$${\text {b}{}{}} {\bar{{\text {b}{}{}}}{}{}} {\text {b}{}{}} {\bar{{\text {b}{}{}}}{}{}} $$$\text{b}\overline{\text{b}}\text{b}\overline{\text{b}}$final state is developed to derive the background model and extract the signal. The data are found to be consistent, within uncertainties, with the SM predictions. The observed (expected) upper limits at 95% confidence level are found to be 3.8 (3.8) and 5.0 (2.9) times the SM prediction for the$${\text {Z}{}{}} {\text {Z}{}{}} $$$\text{Z}\text{Z}$and$${\text {Z}{}{}} {\text {H}{}{}} $$$\text{Z}\text{H}$production cross sections, respectively.

A search for heavy neutral leptons (HNLs) decaying in the CMS muon system is presented. A data sample is used corresponding to an integrated luminosity of$138{\mathrm{fb}}^{-1}$of proton-proton collisions at$\sqrt{s}=13\mathrm{TeV}$, recorded at the CERN LHC in 2016–2018. Decay products of long-lived HNLs could interact with the shielding materials in the CMS muon system and create hadronic and electromagnetic showers detected in the muon chambers. This distinctive signature provides a unique handle to search for HNLs with masses below 4 GeV and proper decay lengths of the order of meters. The signature is sensitive to HNL couplings to all three generations of leptons. Candidate events are required to contain a prompt electron or muon originating from a vertex on the beam axis and a displaced shower in the muon chambers. No significant deviations from the standard model background expectation are observed. In the electron (muon) channel, the most stringent limits to date are set for HNLs in the mass range of 2.1–3.0 (1.9–3.3) GeV, reaching mixing matrix element squared values as low as$8.6(4.6)\times {10}^{-6}$.