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Using proton–proton collision data corresponding to an integrated luminosity of $$140\\hbox { fb}^{-1}$$ 140 fb - 1 collected by the CMS experiment at $$\\sqrt{s}= 13\\,\\text {Te}\\hspace{-.08em}\\text {V} $$ s = 13 Te V , the $${{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{\\text {J}/\\uppsi }} {{{\\Xi }} ^{{-}}} {{\\text {K}} ^{{+}}} $$ Λ b 0 → J / ψ Ξ - K + decay is observed for the first time, with a statistical significance exceeding 5 standard deviations. The relative branching fraction, with respect to the $${{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{{\\uppsi }} ({2\\textrm{S}})} {{\\Lambda }} $$ Λ b 0 → ψ ( 2 S ) Λ decay, is measured to be $$\\mathcal {B}({{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{\\text {J}/\\uppsi }} {{{\\Xi }} ^{{-}}} {{\\text {K}} ^{{+}}} )/\\mathcal {B}({{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{{\\uppsi }} ({2\\textrm{S}})} {{\\Lambda }} ) = [3.38\\pm 1.02\\pm 0.61\\pm 0.03]\\%$$ B ( Λ b 0 → J / ψ Ξ - K + ) / B ( Λ b 0 → ψ ( 2 S ) Λ ) = [ 3.38 ± 1.02 ± 0.61 ± 0.03 ] % , where the first uncertainty is statistical, the second is systematic, and the third is related to the uncertainties in $$\\mathcal {B}({{{\\uppsi }} ({2\\textrm{S}})} \\rightarrow {{\\text {J}/\\uppsi }} {{{\\uppi }} ^{{+}}} {{{\\uppi }} ^{{-}}} )$$ B ( ψ ( 2 S ) → J / ψ π + π - ) and $$\\mathcal {B}({{{\\Xi }} ^{{-}}} \\rightarrow {{\\Lambda }} {{{\\uppi }} ^{{-}}} )$$ B ( Ξ - → Λ π - ) .

The production of prompt $$ {\\Lambda}_{\\textrm{c}}^{+} $$ Λ c + baryons is measured via the exclusive decay channel $$ {\\Lambda}_{\\textrm{c}}^{+}\\to p{\\textrm{K}}^{-}{\\pi}^{+} $$ Λ c + → p K − π + at a center-of-mass energy per nucleon pair of 5.02 TeV, using proton-proton (pp) and lead-lead (PbPb) collision data collected by the CMS experiment at the CERN LHC. The pp and PbPb data were obtained in 2017 and 2018 with integrated luminosities of 252 and 0.607 nb − 1 , respectively. The measurements are performed within the $$ {\\Lambda}_{\\textrm{c}}^{+} $$ Λ c + rapidity interval | y | < 1 with transverse momentum ( p T ) ranges of 3–30 and 6–40 GeV/ c for pp and PbPb collisions, respectively. Compared to the yields in pp collisions scaled by the expected number of nucleon-nucleon interactions, the observed yields of $$ {\\Lambda}_{\\textrm{c}}^{+} $$ Λ c + with p T > 10 GeV/ c are strongly suppressed in PbPb collisions. The level of suppression depends significantly on the collision centrality. The $$ {\\Lambda}_{\\textrm{c}}^{+} $$ Λ c + / D 0 production ratio is similar in PbPb and pp collisions at p T > 10 GeV/ c , suggesting that the coalescence process does not play a dominant role in prompt $$ {\\Lambda}_{\\textrm{c}}^{+} $$ Λ c + baryon production at higher p T .

A search for exotic decays of the Higgs boson ( $$\\text {H}$$ H) with a mass of 125 $$\\,\\text {Ge}\\hspace{-.08em}\\text {V}$$ GeV to a pair of light pseudoscalars $$\\text {a}_{1} $$ a1 is performed in final states where one pseudoscalar decays to two $${\\textrm{b}}$$ b quarks and the other to a pair of muons or $$\\tau $$ τ leptons. A data sample of proton–proton collisions at $$\\sqrt{s}=13\\,\\text {Te}\\hspace{-.08em}\\text {V} $$ s=13TeV corresponding to an integrated luminosity of 138 $$\\,\\text {fb}^{-1}$$ fb-1 recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level ( $$\\text {CL}$$ CL) on the Higgs boson branching fraction to $$\\upmu \\upmu \\text{ b } \\text{ b } $$ μμbb and to $$\\uptau \\uptau \\text{ b } \\text{ b },$$ ττbb, via a pair of $$\\text {a}_{1} $$ a1s. The limits depend on the pseudoscalar mass $$m_{\\text {a}_{1}}$$ ma1 and are observed to be in the range (0.17–3.3)  $$\\times 10^{-4}$$ ×10-4 and (1.7–7.7)  $$\\times 10^{-2}$$ ×10-2 in the $$\\upmu \\upmu \\text{ b } \\text{ b } $$ μμbb and $$\\uptau \\uptau \\text{ b } \\text{ b } $$ ττbb final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction $${\\mathcal {B}}(\\text {H} \\rightarrow \\text {a}_{1} \\text {a}_{1} \\rightarrow \\ell \\ell \\text{ b } \\text{ b})$$ B(H→a1a1→ℓℓbb) at 95% $$\\text {CL}$$ CL, with $$\\ell $$ ℓ being a muon or a $$\\uptau $$ τ lepton. For different types of 2HDM+S, upper bounds on the branching fraction $${\\mathcal {B}}(\\text {H} \\rightarrow \\text {a}_{1} \\text {a}_{1} )$$ B(H→a1a1) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, $${\\mathcal {B}}(\\text {H} \\rightarrow \\text {a}_{1} \\text {a}_{1} )$$ B(H→a1a1) values above 0.23 are excluded at 95% $$\\text {CL}$$ CL for $$m_{\\text {a}_{1}}$$ ma1 values between 15 and 60 $$\\,\\text {Ge}\\hspace{-.08em}\\text {V}$$ GeV.

A measurement is presented of a ratio observable that provides a measure of the azimuthal correlations among jets with large transverse momentum $$p_{\\textrm{T}}$$ pT. This observable is measured in multijet events over the range of $$p_{\\textrm{T}} = 360$$ pT=360– $$3170\\,\\text {Ge}\\hspace{-.08em}\\text {V} $$ 3170GeV based on data collected by the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 $$\\,\\text {Te}\\hspace{-.08em}\\text {V}$$ TeV, corresponding to an integrated luminosity of 134 $$\\,\\text {fb}^{-1}$$ 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 $$\\alpha _\\textrm{S} (m_{{\\textrm{Z}}}) =0.1177 \\pm 0.0013\\, \\text {(exp)} _{-0.0073}^{+0.0116} \\,\\text {(theo)} = 0.1177_{-0.0074}^{+0.0117}$$ αS(mZ)=0.1177±0.0013(exp)-0.0073+0.0116(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 $$\\alpha _\\textrm{S}$$ αS in the $$\\,\\text {Te}\\hspace{-.08em}\\text {V}$$ TeV region shows no deviation from the expected NLO pQCD behaviour.

Using proton–proton collision data corresponding to an integrated luminosity of $$140\\hbox { fb}^{-1}$$ 140fb-1 collected by the CMS experiment at $$\\sqrt{s}= 13\\,\\text {Te}\\hspace{-.08em}\\text {V} $$ s=13TeV, the $${{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{\\text {J}/\\uppsi }} {{{\\Xi }} ^{{-}}} {{\\text {K}} ^{{+}}} $$ Λb0→J/ψΞ-K+ decay is observed for the first time, with a statistical significance exceeding 5 standard deviations. The relative branching fraction, with respect to the $${{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{{\\uppsi }} ({2\\textrm{S}})} {{\\Lambda }} $$ Λb0→ψ(2S)Λ decay, is measured to be $$\\mathcal {B}({{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{\\text {J}/\\uppsi }} {{{\\Xi }} ^{{-}}} {{\\text {K}} ^{{+}}} )/\\mathcal {B}({{{\\Lambda }} _{\\text {b}}^{{0}}} \\rightarrow {{{\\uppsi }} ({2\\textrm{S}})} {{\\Lambda }} ) = [3.38\\pm 1.02\\pm 0.61\\pm 0.03]\\%$$ B(Λb0→J/ψΞ-K+)/B(Λb0→ψ(2S)Λ)=[3.38±1.02±0.61±0.03]%, where the first uncertainty is statistical, the second is systematic, and the third is related to the uncertainties in $$\\mathcal {B}({{{\\uppsi }} ({2\\textrm{S}})} \\rightarrow {{\\text {J}/\\uppsi }} {{{\\uppi }} ^{{+}}} {{{\\uppi }} ^{{-}}} )$$ B(ψ(2S)→J/ψπ+π-) and $$\\mathcal {B}({{{\\Xi }} ^{{-}}} \\rightarrow {{\\Lambda }} {{{\\uppi }} ^{{-}}} )$$ B(Ξ-→Λπ-).

A study of the anomalous couplings of the Higgs boson to vector bosons, including $${\\textit{CP}}$$ 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 $$\\,\\text {fb}^{-1}$$ fb-1. The different-flavor dilepton $$({\\textrm{e}} {{\\upmu }})$$ (eμ) 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 search for exotic decays of the Higgs boson ( ) with a mass of 125 to a pair of light pseudoscalars is performed in final states where one pseudoscalar decays to two quarks and the other to a pair of muons or leptons. A data sample of proton-proton collisions at corresponding to an integrated luminosity of 138 recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level ( ) on the Higgs boson branching fraction to and to via a pair of s. The limits depend on the pseudoscalar mass and are observed to be in the range (0.17-3.3)  and (1.7-7.7)  in the and final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction at 95% , with being a muon or a lepton. For different types of 2HDM+S, upper bounds on the branching fraction are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, values above 0.23 are excluded at 95% for values between 15 and 60 .

The first search for nonresonant production of Higgs boson pairs (HH) with one H decaying into four leptons and the other into a pair of b quarks is presented, using proton-proton collisions recorded at a center-of-mass energy of$$ \\sqrt{s} $$s = 13 TeV by the CMS experiment. The analyzed data correspond to an integrated luminosity of 138 fb − 1 . A 95% confidence level upper limit of 32.4 is set on the signal strength modifier μ , defined as the ratio of the observed HH production rate in the$$ \\textrm{HH}\\to {\\textrm{ZZ}}^{\\ast}\\textrm{b}\\overline{\\textrm{b}}\\to 4\\ell \\textrm{b}\\overline{\\textrm{b}} $$HH → ZZ ∗ b b ¯ → 4 ℓ b b ¯ decay channel to the standard model (SM) expectation. Possible modifications of the H trilinear coupling λ HHH with respect to the SM value are investigated. The coupling modifier κ λ , defined as λ HHH divided by its SM prediction, is constrained to be within the observed (expected) range − 8 . 8 ( − 9 . 8) < κ λ < 13 . 4 (15 . 0) at 95% confidence level.

A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at $${\\sqrt{s}=13\\,\\text {Te}\\hspace{-.08em}\\text {V}}$$ s = 13 Te V by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 $$\\,\\text {fb}^{-1}$$ fb - 1 . The 95% confidence level upper limit set on the branching fraction of the 125 $$\\,\\text {Ge}\\hspace{-.08em}\\text {V}$$ Ge V Higgs boson to invisible particles, $${\\mathcal {B}({\\textrm{H}} \\rightarrow \\text {inv})}$$ B ( H → inv ) , is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous $${\\mathcal {B}({\\textrm{H}} \\rightarrow \\text {inv})}$$ B ( H → inv ) searches carried out at $${\\sqrt{s}=7}$$ s = 7 , 8, and 13 $$\\,\\text {Te}\\hspace{-.08em}\\text {V}$$ Te V in complementary production modes. The combined upper limit at 95% confidence level on $${\\mathcal {B}({\\textrm{H}} \\rightarrow \\text {inv})}$$ B ( H → inv ) is 0.15 (0.08 expected).

Measurements of Higgs boson production, where the Higgs boson decays into a pair of $$\\uptau $$ τ leptons, are presented, using a sample of proton-proton collisions collected with the CMS experiment at a center-of-mass energy of \"Equation missing\" , corresponding to an integrated luminosity of 138 $$\\,\\text {fb}^{-1}$$ fb - 1 . Three analyses are presented. Two are targeting Higgs boson production via gluon fusion and vector boson fusion: a neural network based analysis and an analysis based on an event categorization optimized on the ratio of signal over background events. These are complemented by an analysis targeting vector boson associated Higgs boson production. Results are presented in the form of signal strengths relative to the standard model predictions and products of cross sections and branching fraction to $$\\uptau $$ τ leptons, in up to 16 different kinematic regions. For the simultaneous measurements of the neural network based analysis and the analysis targeting vector boson associated Higgs boson production signal strengths are found to be $$0.82\\pm 0.11$$ 0.82 ± 0.11 for inclusive Higgs boson production, $$0.67\\pm 0.19$$ 0.67 ± 0.19 ( $$0.81\\pm 0.17$$ 0.81 ± 0.17 ) for the production mainly via gluon fusion (vector boson fusion), and $$1.79\\pm 0.45$$ 1.79 ± 0.45 for vector boson associated Higgs boson production.