Search for heavy resonances in the W/Z-tagged dijet mass spectrum in pp collisions at 7 TeV

A search has been made for massive resonances decaying into a quark and a vector boson, qW or qZ, or a pair of vector bosons, WW, WZ, or ZZ, where each vector boson decays to hadronic final states. This search is based on a data sample corresponding to an integrated luminosity of 5.0 fb^-^1 of proton-proton collisions collected in the CMS experiment at the LHC in 2011 at a center-of-mass energy of 7 TeV. For sufficiently heavy resonances the decay products of each vector boson are merged into a single jet, and the event effectively has a dijet topology. The background from QCD dijet events is reduced using recently developed techniques that resolve jet substructure. A 95% CL lower limit is set on the mass of excited quark resonances decaying into qW (qZ) at 2.38 TeV (2.15 TeV) and upper limits are set on the cross section for resonances decaying to qW, qZ, WW, WZ, or ZZ final states.Peer Reviewe

Search for a non-standard-model Higgs boson decaying to a pair of new light bosons in four-muon final states

Results are reported from a search for non-standard-model Higgs boson decays to pairs of new light bosons, each of which decays into the μ+μ− final state. The new bosons may be produced either promptly or via a decay chain. The data set corresponds to an integrated luminosity of 5.3 fb−1 of proton–proton collisions at View the MathML source, recorded by the CMS experiment at the LHC in 2011. Such Higgs boson decays are predicted in several scenarios of new physics, including supersymmetric models with extended Higgs sectors or hidden valleys. Thus, the results of the search are relevant for establishing whether the new particle observed in Higgs boson searches at the LHC has the properties expected for a standard model Higgs boson. No excess of events is observed with respect to the yields expected from standard model processes. A model-independent upper limit of 0.86±0.06 fb on the product of the cross section times branching fraction times acceptance is obtained. The results, which are applicable to a broad spectrum of new physics scenarios, are compared with the predictions of two benchmark models as functions of a Higgs boson mass larger than 86 GeV/c2 and of a new light boson mass within the range 0.25–3.55 GeV/c2Peer Reviewe

Inclusive search for supersymmetry using the razor variables in pppp collisions at s=7\sqrt{s}=7 TeV

An inclusive search is presented for new heavy particle pairs produced in $\sqrt{s}$ = 7 TeV proton-proton collisions at the LHC using 4.7 +/- 0.1 inverse femtobarns of integrated luminosity. The selected events are analyzed in the 2D razor space of MR, an event-by-event indicator of the heavy particle mass scale, and R, a dimensionless variable related to the missing transverse energy. The third-generation sector is probed using the event heavy-flavor content. The search is sensitive to generic supersymmetry models with minimal assumptions about the superpartner decay chains. No excess is observed in the number of events beyond that predicted by the standard model. Exclusion limits are derived in the CMSSM framework as well as for simplified models. Within the CMSSM parameter space considered, gluino masses up to 800 GeV and squark masses up to 1.35 TeV are excluded at 95% confidence level depending on the model parameters. The direct production of pairs of stop or sbottom quarks is excluded for masses as high as 400 GeV.Peer Reviewe

Search for long-lived particles decaying to photons and missing energy in proton-proton collisions at s=7\sqrt{s}=7 TeV

Results are presented from a search for long-lived neutralinos decaying into a photon and an invisible particle, a signature associated with gauge-mediated supersymmetry breaking in supersymmetric models. The analysis is based on a 4.9 inverse femtobarn sample of proton-proton collisions at $\sqrt{s}$ = 7 TeV, collected with the CMS detector at the LHC. The missing transverse energy and the time of arrival of the photon at the electromagnetic calorimeter are used to search for an excess of events over the expected background. No significant excess is observed, and lower limits at the 95% confidence level are obtained on the mass of the lightest neutralino, m(neutralino) > 220 GeV (for c tau 6000 mm (for m(neutralino) < 150 GeV).Peer Reviewe

Search for tt‾ \mathrm{t}\overline{\mathrm{t}} resonances in highly boosted lepton+jets and fully hadronic final states in proton-proton collisions at s=13 \sqrt{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 $\sqrt{s}=13$ 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 $\mathrm{t}\overline{\mathrm{t}}$ 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 $\sqrt{s}=8$ TeV.Peer Reviewe