Search for dark matter produced in association with heavy-flavor quark pairs in proton-proton collisions at √s = 13 TeV

A search is presented for an excess of events with heavy-flavor quark pairs (tt and bb) and a large imbalance in transverse momentum in data from proton–proton collisions at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 2.2fb^(−1) collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in tt and bb final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states

Search for t t-bar resonances in highly boosted lepton+jets and fully hadronic final states in proton-proton collisions at √s = 13 TeV

A search for the production of heavy resonances decaying into top quark-antiquark pairs is presented. The analysis is performed in the lepton+jets and fully hadronic channels using data collected in proton-proton collisions at √s = 13 TeV using the CMS detector at the LHC, corresponding to an integrated luminosity of 2.6 fb^(−1). The selection is optimized for massive resonances, where the top quarks have large Lorentz boosts. No evidence for resonant t t-bar production is found in the data, and upper limits on the production cross section of heavy resonances are set. The exclusion limits for resonances with masses above 2 TeV are significantly improved compared to those of previous analyses at √s = 8 TeV

Combination of searches for heavy resonances decaying to WW, WZ, ZZ, WH, and ZH boson pairs in proton–proton collisions at √s = 8 and 13 TeV

A statistical combination of searches is presented for massive resonances decaying to WW, WZ, ZZ, WH, and ZH boson pairs in proton–proton collision data collected by the CMS experiment at the LHC. The data were taken at centre-of-mass energies of 8 and 13 TeV, corresponding to respective integrated luminosities of 19.7 and up to 2.7 fb^(−1). The results are interpreted in the context of heavy vector triplet and singlet models that mimic properties of composite-Higgs models predicting W′ and Z′ bosons decaying to WZ, WW, WH, and ZH bosons. A model with a bulk graviton that decays into WW and ZZ is also considered. This is the first combined search for WW, WZ, WH, and ZH resonances and yields lower limits on masses at 95% confidence level for W′ and Z′ singlets at 2.3 TeV, and for a triplet at 2.4 TeV. The limits on the production cross section of a narrow bulk graviton resonance with the curvature scale of the warped extra dimension k = 0.5, in the mass range of 0.6 to 4.0 TeV, are the most stringent published to date

Measurement of the B^± Meson Nuclear Modification Factor in Pb-Pb Collisions at √S_(NN) = 5.02 TeV

The differential production cross sections of B^± mesons are measured via the exclusive decay channels B^± → J/ψK^ ±→ μ^+μ^−K^± as a function of transverse momentum in pp and Pb-Pb collisions at a center-of-mass energy √S_(NN) = 5.02  TeV per nucleon pair with the CMS detector at the LHC. The pp(Pb-Pb) data set used for this analysis corresponds to an integrated luminosity of 28.0  pb^(-1) (351  μb^(-1)). The measurement is performed in the B^± meson transverse momentum range of 7 to 50  GeV/c, in the rapidity interval |y| < 2.4. In this kinematic range, a strong suppression of the production cross section by about a factor of 2 is observed in the Pb-Pb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma

Measurements of ttcross sections in association with b jets and inclusive jets and their ratio using dilepton final states in pp collisions at √s = 13 TeV

The cross sections for the production of ttbb and ttjj events and their ratio σ_(ttbb)/_(ttjj) are measured using data corresponding to an integrated luminosity of 2.3 fb^(−1) collected in pp collisions at √s = 13 TeV with the CMS detector at the LHC. Events with two leptons (e or μ) and at least four reconstructed jets, including at least two identified as b quark jets, in the final state are selected. In the full phase space, the measured ratio is 0.022 ± 0.003(stat) ± 0.006(syst), the cross section σ_(ttbb) is 4.0 ± 0.6(stat) ± 1.3(syst)pb and σ_(ttjj) is 184 ± 6(stat) ± 33(syst)pb. The measurements are compared with the standard model expectations obtained from a powheg simulation at next-to-leading-order interfaced with pythia

Search for supersymmetry with Higgs boson to diphoton decays using the razor variables at √s = 13 TeV

An inclusive search for anomalous Higgs boson production in the diphoton decay channel and in association with at least one jet is presented, using LHC proton–proton collision data collected by the CMS experiment at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 35.9fb^(−1). The razor variables M_R and R^2, as well as the momentum and mass resolution of the diphoton system, are used to categorize events into different search regions. The search result is interpreted in the context of strong and electroweak production of supersymmetric particles. We exclude bottom squark pair-production with masses below 450 GeV for bottom squarks decaying to a bottom quark, a Higgs boson, and the lightest supersymmetric particle (LSP) for LSP masses below 250 GeV. For wino-like chargino–neutralino production, we exclude charginos with mass below 170 GeV for LSP masses below 25 GeV. In the GMSB scenario, we exclude charginos with mass below 205 GeV for neutralinos decaying to a Higgs boson and a goldstino LSP with 100% branching fraction

Search for heavy resonances that decay into a vector boson and a Higgs boson in hadronic final states at √s = 13s TeV

A search for heavy resonances with masses above 1 TeV, decaying to final states containing a vector boson and a Higgs boson, is presented. The search considers hadronic decays of the vector boson, and Higgs boson decays to b quarks. The decay products are highly boosted, and each collimated pair of quarks is reconstructed as a single, massive jet. The analysis is performed using a data sample collected in 2016 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9fb^(−1). The data are consistent with the background expectation and are used to place limits on the parameters of a theoretical model with a heavy vector triplet. In the benchmark scenario with mass-degenerate W′ and Z′ bosons decaying predominantly to pairs of standard model bosons, for the first time heavy resonances for masses as high as 3.3TeV are excluded at 95% confidence level, setting the most stringent constraints to date on such states decaying into a vector boson and a Higgs boson

Observation of Correlated Azimuthal Anisotropy Fourier Harmonics in pp and p+Pb Collisions at the LHC

The azimuthal anisotropy Fourier coefficients (v_n) in 8.16 TeV p+Pb data are extracted via long-range two-particle correlations as a function of the event multiplicity and compared to corresponding results in pp and PbPb collisions. Using a four-particle cumulant technique, v_n correlations are measured for the first time in pp and p+Pb collisions. The v_2 and v_4 coefficients are found to be positively correlated in all collision systems. For high-multiplicity p+Pb collisions, an anticorrelation of v_2 and v_3 is observed, with a similar correlation strength as in PbPb data at the same multiplicity. The new correlation results strengthen the case for a common origin of the collectivity seen in p+Pb and PbPb collisions in the measured multiplicity range

Search for physics beyond the standard model in events with two leptons of same sign, missing transverse momentum, and jets in proton–proton collisions at √s = 13 TeV

A data sample of events from proton–proton collisions with two isolated same-sign leptons, missing transverse momentum, and jets is studied in a search for signatures of new physics phenomena by the CMS Collaboration at the LHC. The data correspond to an integrated luminosity of 35.9 fb^(−1), and a center-of-mass energy of 13 TeV. The properties of the events are consistent with expectations from standard model processes, and no excess yield is observed. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos, squarks, and same-sign top quarks, as well as top-quark associated production of a heavy scalar or pseudoscalar boson decaying to top quarks, and on the standard model production of events with four top quarks. The observed lower mass limits are as high as 1500 GeV for gluinos, 830 GeV for bottom squarks. The excluded mass range for heavy (pseudo)scalar bosons is 350–360 (350–410) GeV. Additionally, model-independent limits in several topological regions are provided, allowing for further interpretations of the results