Measurement of the Higgs boson production via vector boson fusion and its decay into bottom quarks in proton-proton collisions at s \sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2308.01253v2 [hep-ex], https://arxiv.org/abs/2308.01253v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-22-009 (CMS Public Pages). Report number: CMS-HIG-22-009, CERN-EP-2023-110.A measurement of the Higgs boson (H) production via vector boson fusion (VBF) and its decay into a bottom quark-antiquark pair (bb¯) is presented using proton-proton collision data recorded by the CMS experiment at s√ = 13 TeV and corresponding to an integrated luminosity of 90.8 fb−1. Treating the gluon-gluon fusion process as a background and constraining its rate to the value expected in the standard model (SM) within uncertainties, the signal strength of the VBF process, defined as the ratio of the observed signal rate to that predicted by the SM, is measured to be μqqHHbb¯ = 1.01 +0.55−0.46. The VBF signal is observed with a significance of 2.4 standard deviations relative to the background prediction, while the expected significance is 2.7 standard deviations. Considering inclusive Higgs boson production and decay into bottom quarks, the signal strength is measured to be μincl.Hbb¯ = 0.99 +0.48−0.41, corresponding to an observed (expected) significance of 2.6 (2.9) standard deviations.SCOAP3, STFC; Marie-Curie program and the European Research Council and Horizon 2020 Gran

Search for dark matter particles in W+W− events with transverse momentum imbalance in proton-proton collisions at √s = 13 TeV

A preprint version of the article is available at arXiv:2310.12229v2 [hep-ex], https://arxiv.org/abs/2310.12229v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-21-012 (CMS Public Pages).A search for dark matter particles is performed using events with a pair of W bosons and large missing transverse momentum. Candidate events are selected by requiring one or two leptons (ℓ = electrons or muons). The analysis is based on proton-proton collision data collected at a center-of-mass energy of 13 TeV by the CMS experiment at the LHC and corresponding to an integrated luminosity of 138 fb−1. No significant excess over the expected standard model background is observed in the ℓνqq and 2ℓ2ν final states of the W+W− boson pair. Limits are set on dark matter production in the context of a simplified dark Higgs model, with a dark Higgs boson mass above the W+W− mass threshold. The dark matter phase space is probed in the mass range 100–300 GeV, extending the scope of previous searches. Current exclusion limits are improved in the range of dark Higgs masses from 160 to 250 GeV, for a dark matter mass of 200 GeV.SCOAP3

Search for long-lived heavy neutral leptons with lepton flavour conserving or violating decays to a jet and a charged lepton

A preprint version of the article is available at arXiv:2312.07484v3 [hep-ex], https://arxiv.org/abs/2312.07484 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-21-013 (CMS Public Pages)A search for long-lived heavy neutral leptons (HNLs) is presented, which considers the hadronic final state and coupling scenarios involving all three lepton generations in the 2-20 GeV HNL mass range for the first time. Events comprising two leptons (electrons or muons) and jets are analyzed in a data sample of proton-proton collisions, recorded with the CMS experiment at the CERN LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb−1. A novel jet tagger, based on a deep neural network, has been developed to identify jets from an HNL decay using various features of the jet and its constituent particles. The network output can be used as a powerful discriminating tool to probe a broad range of HNL lifetimes and masses. Contributions from background processes are determined from data. No excess of events in data over the expected background is observed. Upper limits on the HNL production cross section are derived as functions of the HNL mass and the three coupling strengths VℓN to each lepton generation ℓ and presented as exclusion limits in the coupling-mass plane, as lower limits on the HNL lifetime, and on the HNL mass. In this search, the most stringent limit on the coupling strength is obtained for pure muon coupling scenarios; values of |VμN|2 > 5 (4) × 10−7 are excluded for Dirac (Majorana) HNLs with a mass of 10 GeV at a confidence level of 95% that correspond to proper decay lengths of 17 (10) mm.SCOAP3

Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at √s = 13 TeV

Data availability: Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS policy as stated in “CMS data preservation, re-use and open access policy” available online at: https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032&filename=CMSDataPolicyV1.2.pdf&version=2 .A preprint of this article is available online at arXiv:2311.03261v2 [hep-ex] https://arxiv.org/abs/2311.03261v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-22-010 (CMS Public Pages)A search is presented for new Higgs bosons in proton-proton (pp) collision events in which a same-sign top quark pair is produced in association with a jet, via the pp → tH/A → tt¯c and pp → tH/A → tt¯u processes. Here, H and A represent the extra scalar and pseudoscalar boson, respectively, of the second Higgs doublet in the generalized two-Higgs-doublet model (g2HDM). The search is based on pp collision data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 138 fb−1. Final states with a same-sign lepton pair in association with jets and missing transverse momentum are considered. New Higgs bosons in the 200-1000 GeV mass range and new Yukawa couplings between 0.1 and 1.0 are targeted in the search, for scenarios in which either H or A appear alone, or in which they coexist and interfere. No significant excess above the standard model prediction is observed. Exclusion limits are derived in the context of the g2HDM.SCOAP3

Search for direct production of GeV-scale resonances decaying to a pair of muons in proton-proton collisions at s\sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2309.16003v2 [hep-ex], https://arxiv.org/abs/2309.16003v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-21-005 (CMS Public Pages). Report number: CMS-EXO-21-005, CERN-EP-2023-165.A search for direct production of low-mass dimuon resonances is performed using s√ = 13 TeV proton-proton collision data collected by the CMS experiment during the 2017-2018 operation of the CERN LHC with an integrated luminosity of 96.6 fb−1. The search exploits a dedicated high-rate trigger stream that records events with two muons with transverse momenta as low as 3 GeV but does not include the full event information. The search is performed by looking for narrow peaks in the dimuon mass spectrum in the ranges of 1.1-2.6 GeV and 4.2-7.9 GeV. No significant excess of events above the expectation from the standard model background is observed. Model-independent limits on production rates of dimuon resonances within the experimental fiducial acceptance are set. Competitive or world's best limits are set at 90% confidence level for a minimal dark photon model and for a scenario with two Higgs doublets and an extra complex scalar singlet (2HDM+S). Values of the squared kinetic mixing coefficient ε2 in the dark photon model above 10−6 are excluded over most of the mass range of the search. In the 2HDM+S, values of the mixing angle sin(θH) above 0.08 are excluded over most of the mass range of the search with a fixed ratio of the Higgs doublets vacuum expectation tanβ = 0.5.SCOAP3

Search for W′ bosons decaying to a top and a bottom quark in leptonic final states in proton-proton collisions at s \sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2310.19893v1 [hep-ex], https://arxiv.org/abs/2310.19893v1 . Comments: Submitted to the Journal of High Energy Physics. All figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/B2G-20-012 (CMS Public Pages). Report number: CMS-B2G-20-012, CERN-EP-2023-213.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 (mW′) 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 mW′ 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%. These are the most stringent limits to date on this W' boson decay channel.SCOAP3

Search for physics beyond the standard model in top quark production with additional leptons in the context of effective field theory

A preprint version of the article is available at arXiv:2307.15761v2 [hep-ex], https://arxiv.org/abs/2307.15761v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-22-006 (CMS Public Pages). Report number: CMS-TOP-22-006, CERN-EP-2023-124.A search for new physics in top quark production with additional final-state leptons is performed using data collected by the CMS experiment in proton-proton collisions at √s = 13 TeV at the LHC during 2016-2018. The data set corresponds to an integrated luminosity of 138 fb−1. Using the framework of effective field theory (EFT), potential new physics effects are parametrized in terms of 26 dimension-six EFT operators. The impacts of EFT operators are incorporated through the event-level reweighting of Monte Carlo simulations, which allows for detector-level predictions. The events are divided into several categories based on lepton multiplicity, total lepton charge, jet multiplicity, and b-tagged jet multiplicity. Kinematic variables corresponding to the transverse momentum (pT) of the leading pair of leptons and/or jets as well as the pT of on-shell Z bosons are used to extract the 95% confidence intervals of the 26 Wilson coefficients corresponding to these EFT operators. No significant deviation with respect to the standard model prediction is found.SCOAP3

Observation of four top quark production in proton-proton collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.svg"><mml:msqrt><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msqrt><mml:mo linebreak="goodbreak" linebreakstyle="after">=</mml:mo><mml:mn>13</mml:mn><mml:mspace width="0.2em" /><mml:mtext>TeV</mml:mtext></mml:math>

Data availability: Will be supplied with proofs.A preprint of this article was made available on arXiv, arXiv:2305.13439 [hep-ex]. The preprint was replaced with the published version. All the figures and tables can be found at: http://cms-results.web.cern.ch/cms-results/public-results/publications/TOP-22-013 (CMS Public Pages).Report number: CMS-TOP-22-013, CERN-EP-2023-090The observation of the production of four top quarks in proton-proton collisions is reported, based on a data sample collected by the CMS experiment at a center-of-mass energy of 13 TeV in 2016–2018 at the CERN LHC and corresponding to an integrated luminosity of 138 fb−1. Events with two same-sign, three, or four charged leptons (electrons and muons) and additional jets are analyzed. Compared to previous results in these channels, updated identification techniques for charged leptons and jets originating from the hadronization of b quarks, as well as a revised multivariate analysis strategy to distinguish the signal process from the main backgrounds, lead to an improved expected signal significance of 4.9 standard deviations above the background-only hypothesis. Four top quark production is observed with a significance of 5.6 standard deviations, and its cross section is measured to be 17.7 +3.7−3.5 (stat) +2.3−1.9 (syst) fb, in agreement with the available standard model predictions.SCOAP3

Search for the lepton-flavor violating decay of the Higgs boson and additional Higgs bosons in the eμμ final state in proton-proton collisions at s\sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2305.18106v2 [hep-ex], https://arxiv.org/abs/2305.18106v2 . Comments: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables can be found at https://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-22-002 (CMS Public Pages). Report number: CMS-HIG-22-002, CERN-EP-2023-061.A search for the lepton-flavor violating decay of the Higgs boson and potential additional Higgs bosons with a mass in the range 110-160 GeV to an e±μ∓ pair is presented. The search is performed with a proton-proton collision dataset at a center-of-mass energy of 13 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb−1. No excess is observed for the Higgs boson. The observed (expected) upper limit on the e±μ∓ branching fraction for it is determined to be 4.4 (4.7) × 10−5 at 95% confidence level, the most stringent limit set thus far from direct searches. The largest excess of events over the expected background in the full mass range of the search is observed at an e±μ∓ invariant mass of approximately 146 GeV with a local (global) significance of 3.8 (2.8) standard deviations.SCOAP3