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Measurements of fiducial and total inclusive cross sections for W and Z boson production are presented in proton-proton collisions at$$ \\sqrt{s} $$s = 5.02 and 13 TeV. Electron and muon decay modes ( ℓ = e or μ ) are studied in the data collected with the CMS detector in 2017, in dedicated runs with reduced instantaneous luminosity. The data sets correspond to integrated luminosities of 298 ± 6 pb − 1 at 5.02 TeV and 206 ± 5 pb − 1 at 13 TeV. Measured values of the products of the total inclusive cross sections and the branching fractions at 5.02 TeV are σ (pp → W + X)$$ \\mathcal{B} $$B (W → ℓν ) = 7300 ± 10 (stat) ± 60 (syst) ± 140 (lumi) pb, and σ (pp → Z+X)$$ \\mathcal{B} $$B (Z → ℓ + ℓ − ) = 669 ± 2 (stat) ± 6 (syst) ± 13 (lumi) pb for the dilepton invariant mass in the range of 60–120 GeV. The corresponding results at 13 TeV are 20480 ± 10 (stat) ± 170 (syst) ± 470 (lumi) pb and 1952 ± 4 (stat) ± 18 (syst) ± 45 (lumi) pb. The measured values agree with cross section calculations at next-to-next-to-leading-order in perturbative quantum chromodynamics. Fiducial and total inclusive cross sections, ratios of cross sections of W + and W − production as well as inclusive W and Z boson production, and ratios of these measurements at 5.02 and 13 TeV are reported.

Abstract A search is presented for a new scalar resonance, X, decaying to a standard model Higgs boson and another new scalar particle, Y, in the final state where the Higgs boson decays to a $$\\text{b}\\overline{\\text{b} }$$ pair, while the Y particle decays to a pair of photons. The search is performed in the mass range 240–1000 GeV for the resonance X, and in the mass range 70–800 GeV for the particle Y, using proton-proton collision data collected by the CMS experiment at $$\\sqrt{s}=13$$ TeV, corresponding to an integrated luminosity of 132 fb −1. In general, the data are found to be compatible with the standard model expectation. Observed (expected) upper limits at 95% confidence level on the product of the production cross section and the relevant branching fraction are extracted for the X → YH process, and are found to be within the range of 0.05–2.69 (0.08–1.94) fb, depending on m X and m Y. The most significant deviation from the background-only hypothesis is observed for X and Y masses of 300 and 77 GeV, respectively, with a local (global) significance of 3.33 (0.65) standard deviations.

A measurement is performed of Higgs bosons produced with high transverse momentum ( p T ) via vector boson or gluon fusion in proton-proton collisions. The result is based on a data set with a center-of-mass energy of 13 TeV collected in 2016–2018 with the CMS detector at the LHC and corresponds to an integrated luminosity of 138 fb − 1 . The decay of a high- p T Higgs boson to a boosted bottom quark-antiquark pair is selected using large-radius jets and employing jet substructure and heavy-flavor taggers based on machine learning techniques. Independent regions targeting the vector boson and gluon fusion mechanisms are defined based on the topology of two quark-initiated jets with large pseudorapidity separation. The signal strengths for both processes are extracted simultaneously by performing a maximum likelihood fit to data in the large-radius jet mass distribution. The observed signal strengths relative to the standard model expectation are$$ {4.9}_{-1.6}^{+1.9} $$4.9 − 1.6 + 1.9 and$$ {1.6}_{-1.5}^{+1.7} $$1.6 − 1.5 + 1.7 for the vector boson and gluon fusion mechanisms, respectively. A differential cross section measurement is also reported in the simplified template cross section framework.

A search for Higgs boson pair (HH) production in association with a vector boson V (W or Z boson) is presented. The search is based on proton-proton collision data at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb − 1 . Both hadronic and leptonic decays of V bosons are used. The leptons considered are electrons, muons, and neutrinos. The HH production is searched for in the$$ \\textrm{b}\\overline{\\textrm{b}}\\textrm{b}\\overline{\\textrm{b}} $$b b ¯ b b ¯ decay channel. An observed (expected) upper limit at 95% confidence level of VHH production cross section is set at 294 (124) times the standard model prediction. Constraints are also set on the modifiers of the Higgs boson trilinear self-coupling, k λ , assuming k 2V = 1, and vice versa on the coupling of two Higgs bosons with two vector bosons, k 2V . The observed (expected) 95% confidence intervals of these coupling modifiers are − 37.7 < k λ < 37.2 ( − 30.1 < k λ < 28.9) and − 12.2 < k 2V < 13.5 ( − 7.2 < k 2V < 8.9), respectively.

A measurement of the dijet production cross section is reported based on proton–proton collision data collected in 2016 at$$\\sqrt{s}=13\\,\\text {Te}\\hspace{-.08em}\\text {V} $$s = 13 Te V by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of up to 36.3$$\\,\\text {fb}^{-1}$$fb - 1 . Jets are reconstructed with the anti-$$k_{\\textrm{T}} $$k T algorithm for distance parameters of$$R=0.4$$R = 0.4 and 0.8. Cross sections are measured double-differentially (2D) as a function of the largest absolute rapidity$$|y |_{\\text {max}} $$| y | max of the two jets with the highest transverse momenta$$p_{\\textrm{T}}$$p T and their invariant mass$$m_{1,2} $$m 1 , 2 , and triple-differentially (3D) as a function of the rapidity separation$$y^{*} $$y ∗ , the total boost$$y_{\\text {b}} $$y b , and either$$m_{1,2} $$m 1 , 2 or the average$$p_{\\textrm{T}}$$p T of the two jets. The cross sections are unfolded to correct for detector effects and are compared with fixed-order calculations derived at next-to-next-to-leading order in perturbative quantum chromodynamics. The impact of the measurements on the parton distribution functions and the strong coupling constant at the mass of the$${\\text {Z}} $$Z boson is investigated, yielding a value of$$\\alpha _\\textrm{S} (m_{{\\text {Z}}}) =0.1179\\pm 0.0019$$α S ( m Z ) = 0.1179 ± 0.0019 .

A search for Higgs boson pair (HH) production with one Higgs boson decaying to two bottom quarks and the other to two W bosons are presented. The search is done using proton-proton collisions data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb − 1 recorded by the CMS detector at the LHC from 2016 to 2018. The final states considered include at least one leptonically decaying W boson. No evidence for the presence of a signal is observed and corresponding upper limits on the HH production cross section are derived. The limit on the inclusive cross section of the nonresonant HH production, assuming that the distributions of kinematic observables are as expected in the standard model (SM), is observed (expected) to be 14 (18) times the value predicted by the SM, at 95% confidence level. The limits on the cross section are also presented as functions of various Higgs boson coupling modifiers, and anomalous Higgs boson coupling scenarios. In addition, limits are set on the resonant HH production via spin-0 and spin-2 resonances within the mass range 250–900 GeV.

A search is presented for the decay of the 125 GeV Higgs boson (H) to a pair of new light pseudoscalar bosons (a), followed by the prompt decay of each a boson to a bottom quark-antiquark pair,$$ \\textrm{H}\\to \\textrm{aa}\\to \\textrm{b}\\overline{\\textrm{b}}\\textrm{b}\\overline{\\textrm{b}} $$H → aa → b b ¯ b b ¯ . The analysis is performed using a data sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb − 1 . To reduce the background from standard model processes, the search requires the Higgs boson to be produced in association with a leptonically decaying W or Z boson. The analysis probes the production of new light bosons in a 15 < m a < 60 GeV mass range. Assuming the standard model predictions for the Higgs boson production cross sections for pp → WH and ZH, model independent upper limits at 95% confidence level are derived for the branching fraction$$ \\mathcal{B}\\left(\\textrm{H}\\to \\textrm{aa}\\to \\textrm{b}\\overline{\\textrm{b}}\\textrm{b}\\overline{\\textrm{b}}\\right) $$B H → aa → b b ¯ b b ¯ . The combined WH and ZH observed upper limit on the branching fraction ranges from 1.10 for m a = 20 GeV to 0.36 for m a = 60 GeV, complementing other measurements in the μμττ , ττττ and bb ℓℓ ( ℓ = μ , τ ) channels.

A search for W′ bosons decaying to a top and a bottom quark in final states including an electron or a muon is performed with the CMS detector at the LHC. The analyzed data correspond to an integrated luminosity of 138 fb − 1 of proton-proton collisions at a center-of-mass energy of 13 TeV. Good agreement with the standard model expectation is observed and no evidence for the existence of the W′ boson is found over the mass range examined. The largest observed deviation from the standard model expectation is found for a W′ boson mass ($$ {m}_{{\\textrm{W}}^{\\prime }} $$m W ′ ) hypothesis of 3.8 TeV with a relative decay width of 1%, with a local (global) significance of 2.6 (2.0) standard deviations. Upper limits on the production cross sections of W′ bosons decaying to a top and a bottom quark are set. Left- and right-handed W′ bosons with$$ {m}_{{\\textrm{W}}^{\\prime }} $$m W ′ below 3.9 and 4.3 TeV, respectively, are excluded at the 95% confidence level, under the assumption that the new particle has a narrow decay width. Limits are also set for relative decay widths up to 30%.

An inclusive search for long-lived exotic particles (LLPs) decaying to final states with a pair of muons is presented. The search uses data corresponding to an integrated luminosity of 36.6 fb − 1 collected by the CMS experiment from the proton-proton collisions at$$ \\sqrt{s} $$s = 13.6 TeV in 2022, the first year of Run 3 of the CERN LHC. The experimental signature is a pair of oppositely charged muons originating from a secondary vertex spatially separated from the proton-proton interaction point by distances ranging from several hundred μ m to several meters. The sensitivity of the search benefits from new triggers for displaced dimuons developed for Run 3. The results are interpreted in the framework of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons, and of an R -parity violating supersymmetry model, in which long-lived neutralinos decay to a pair of muons and a neutrino. The limits set on these models are the most stringent to date in wide regions of lifetimes for LLPs with masses larger than 10 GeV.

Measurements of inclusive and normalized differential cross sections of the associated production of top quark-antiquark and bottom quark-antiquark pairs,$$ \\textrm{t}\\overline{\\textrm{t}}\\textrm{b}\\overline{\\textrm{b}} $$t t ¯ b b ¯ , are presented. The results are based on data from proton-proton collisions collected by the CMS detector at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb − 1 . The cross sections are measured in the lepton+jets decay channel of the top quark pair, using events containing exactly one isolated electron or muon and at least five jets. Measurements are made in four fiducial phase space regions, targeting different aspects of the$$ \\textrm{t}\\overline{\\textrm{t}}\\textrm{b}\\overline{\\textrm{b}} $$t t ¯ b b ¯ process. Distributions are unfolded to the particle level through maximum likelihood fits, and compared with predictions from several event generators. The inclusive cross section measurements of this process in the fiducial phase space regions are the most precise to date. In most cases, the measured inclusive cross sections exceed the predictions with the chosen generator settings. The only exception is when using a particular choice of dynamic renormalization scale,$$ {\\mu}_{\\textrm{R}}=\\frac{1}{2}{\\prod}_{i=\\textrm{t},\\overline{\\textrm{t}},\\textrm{b},\\overline{\\textrm{b}}}{m}_{\\textrm{T},i}^{1/4} $$μ R = 1 2 ∏ i = t , t ¯ , b , b ¯ m T , i 1 / 4 , where$$ {m}_{\\textrm{T},i}^2={m}_i^2+{p}_{\\textrm{T},i}^2 $$m T , i 2 = m i 2 + p T , i 2 are the transverse masses of top and bottom quarks. The differential cross sections show varying degrees of compatibility with the theoretical predictions, and none of the tested generators with the chosen settings simultaneously describe all the measured distributions.