Search for Higgs boson decays to a Z boson and a photon in proton-proton collisions at s \sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2204.12945v2 [hep-ex], https://arxiv.org/abs/2204.12945v2 . 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-19-014 (CMS Public Pages). Report number: CMS-HIG-19-014, CERN-EP-2022-019.Results are presented from a search for the Higgs boson decay H → Zγ, where Z → ℓ+ℓ− with ℓ = e or μ. The search is performed using a sample of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb^{−1}. Events are assigned to mutually exclusive categories, which exploit differences in both event topology and kinematics of distinct Higgs production mechanisms to enhance signal sensitivity. The signal strength μ, defined as the product of the cross section and the branching fraction [σ(pp → H)B(H → Zγ)] relative to the standard model prediction, is extracted from a simultaneous fit to the ℓ+ℓ−γ invariant mass distributions in all categories and is found to be μ = 2.4 ± 0.9 for a Higgs boson mass of 125.38 GeV. The statistical significance of the observed excess of events is 2.7 standard deviations. This measurement corresponds to σ(pp → H)B(H → Zγ) = 0.21 ± 0.08 pb. The observed (expected) upper limit at 95% confidence level on μ is 4.1 (1.8). The ratio of branching fractions B(H → Zγ)/B(H → γγ) is measured to be 1.5 +0.7−0.6, which agrees with the standard model prediction of 0.69 ± 0.04 at the 1.5 standard deviation level.SCOAP3

Measurements of the Higgs boson production cross section and couplings in the W boson pair decay channel in proton-proton collisions at s\sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2206.09466v2 [hep-ex], https://arxiv.org/abs/2206.09466v2 . 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-20-013 (CMS Public Pages). Report number: CMS-HIG-20-013, CERN-EP-2022-120.Production cross sections of the standard model Higgs boson decaying to a pair of W bosons are measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis targets Higgs bosons produced via gluon fusion, vector boson fusion, and in association with a W or Z boson. Candidate events are required to have at least two charged leptons and moderate missing transverse momentum, targeting events with at least one leptonically decaying W boson originating from the Higgs boson. Results are presented in the form of inclusive and differential cross sections in the simplified template cross section framework, as well as couplings of the Higgs boson to vector bosons and fermions. The data set collected by the CMS detector during 2016-2018 is used, corresponding to an integrated luminosity of 138 fb^−1. The signal strength modifier μ, defined as the ratio of the observed production rate in a given decay channel to the standard model expectation, is measured to be μ = 0.95 +0.10−0.09. All results are found to be compatible with the standard model within the uncertainties.SCOAP3

Evidence for tWZ production in proton-proton collisions at √s=13 TeV in multilepton final states

Data availability - https://www.sciencedirect.com/science/article/pii/S0370269324003733?via%3Dihub#dav0001 [Release and preservation of data used by the CMS Collaboration as the basis for publications is guided by the CMS data preservation, re-use and open access policy (https://cms-docdb.cern.ch/cgi-bin/PublicDocDB/RetrieveFile?docid=6032&filename=CMSDataPolicyV1.2.pdf&version=2)]The first evidence for the standard model production of a top quark in association with a W boson and a Z boson is reported. The measurement is performed in multilepton final states, where the Z boson is reconstructed via its decays to electron or muon pairs. At least one W boson, associated or from top quark decay, decays leptonically, too. The analysed data were recorded by the CMS experiment at the CERN LHC in 2016–2018 in proton-proton collisions at √s=13 TeV, and correspond to an integrated luminosity of 138 fb−1. The measured cross section is 354±54(stat)±95(syst) fb, and corresponds to a statistical significance of 3.4 standard deviations.SCOAP

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

Azimuthal anisotropy of dijet events in PbPb collisions at √sNN = 5.02TeV

A preprint version of the article is available at arXiv - https://arxiv.org/abs/2210.08325The path-length dependent parton energy loss within the dense partonic medium created in lead-lead collisions at a nucleon-nucleon center-of-mass energy of √sNN = 5.02TeV is studied by determining the azimuthal anisotropies for dijets with high transverse momentum. The data were collected by the CMS experiment in 2018 and correspond to an integrated luminosity of 1.69nb−1. For events containing back-to back jets, correlations in relative azimuthal angle and pseudorapidity (η) between jets and hadrons, and between two hadrons, are constructed. The anisotropies are expressed as the Fourier expansion coefficients vn, n = 2–4 of these azimuthal distributions. The dijet vn values are extracted from long-range (1.5 < |∆η| < 2.5) components of these correlations, which suppresses the background contributions from jet fragmentation processes. Positive dijet v2 values are observed which increase from central to more peripheral events, while the v3 and v4 values are consistent with zero within experimental uncertainties.SCOAP

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 long-lived particles using out-of-time trackless jets in proton-proton collisions at √s =13TeV

A search for long-lived particles decaying in the outer regions of the CMS silicon tracker or in the calorimeters is presented. The search is based on a data sample of proton-proton collisions at √s = 13 TeV recorded with the CMS detector at the LHC in 2016–2018, corresponding to an integrated luminosity of 138 fb−1. A novel technique, using nearly trackless and out-of-time jet information combined in a deep neural network discriminator, is employed to identify decays of long-lived particles. The results are interpreted in a simplified model of chargino-neutralino production, where the neutralino is the next-to-lightest supersymmetric particle, is long-lived, and decays to a gravitino and either a Higgs or Z boson. This search is most sensitive to neutralino proper decay lengths of approximately 0.5 m, for which masses up to 1.18 TeV are excluded at 95% confidence level. The current search is the best result to date in the mass range from the kinematic limit imposed by the Higgs boson mass up to 1.8 TeV.SCOAP

Searches for additional Higgs bosons and for vector leptoquarks in ττ final states in proton-proton collisions at s \sqrt{s} = 13 TeV

A preprint version of the article is available at arXiv:2208.02717v2 [hep-ex], https://arxiv.org/abs/2208.02717v2 . 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/HIG-21-001 (CMS Public Pages).Three searches are presented for signatures of physics beyond the standard model (SM) in ττ final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at s√ = 13 TeV, corresponding to an integrated luminosity of 138 fb−1. Upper limits at 95% confidence level (CL) are set on the products of the branching fraction for the decay into τ leptons and the cross sections for the production of a new boson ϕ, in addition to the H(125) boson, via gluon fusion (ggϕ) or in association with b quarks, ranging from O(10 pb) for a mass of 60 GeV to 0.3 fb for a mass of 3.5 TeV each. The data reveal two excesses for ggϕ production with local p-values equivalent to about three standard deviations at mϕ = 0.1 and 1.2 TeV. In a search for t-channel exchange of a vector leptoquark U1, 95% CL upper limits are set on the dimensionless U1 leptoquark coupling to quarks and τ leptons ranging from 1 for a mass of 1 TeV to 6 for a mass of 5 TeV, depending on the scenario. In the interpretations of the M125h and M125h,EFT minimal supersymmetric SM benchmark scenarios, additional Higgs bosons with masses below 350 GeV are excluded at 95% CL.SCOAP3