Search for dark matter and large extra dimensions in monojet events in pp collisions at √s = 7 TeV
Journal of High Energy Physics 2012:9 (2012)
Abstract:
A search has been made for events containing an energetic jet and an imbalance in transverse momentum using a data sample of pp collisions at a center-of-mass energy of 7 TeV. This signature is common to both dark matter and extra dimensions models. The data were collected by the CMS detector at the LHC and correspond to an integrated luminosity of 5.0 fb-1. The number of observed events is consistent with the standard model expectation. Constraints on the dark matter-nucleon scattering cross sections are determined for both spin-independent and spin-dependent interaction models. For the spin-independent model, these are the most constraining limits for a dark matter particle with mass below 3.5 GeV/c2, a region unexplored by direct detection experiments. For the spin-dependent model, these are the most stringent constraints over the 0.1-200 GeV/c2 mass range. The constraints on the Arkani-Hamed, Dimopoulos, and Dvali model parameter M D determined as a function of the number of extra dimensions are also an improvement over the previous results.Search for heavy metastable particles decaying to jet pairs in pp¯ collisions at s=1.96 TeV
Physical Review D American Physical Society (APS) 85:1 (2012) 012007
Search for leptonic decays of W′ bosons in pp collisions at √s = 7 TeV
Journal of High Energy Physics 2012:8 (2012)
Abstract:
A search for a new heavy gauge boson W′ decaying to an electron or muon, plus a low mass neutrino, is presented. This study uses data corresponding to an integrated luminosity of 5.0 fb-1, collected using the CMS detector in pp collisions at a centre-of-mass energy of 7 TeV at the LHC. Events containing a single electron or muon and missing transverse momentum are analyzed. No significant excess of events above the standard model expectation is found in the transverse mass distribution of the lepton-neutrino system, and upper limits for cross sections above different transverse mass thresholds are presented. W′ Mass exclusion limits at 95% CL for a range of W′ models are determined, including a limit of 2.5 TeV for right-handed W bosons with standard-model-like couplings and limits W′ 2.43-2.63 TeV for left-handed W′ bosons, taking into account their interference with the standard model W boson. Exclusion limits have also been set on Kaluza-Klein WKK states in the framework of split universal extra dimensions. © 2012 SISSA.Search for microscopic black holes in pp collisions at √ s = 7 TeV
Journal of High Energy Physics 2012:4 (2012)
Abstract:
A search for microscopic black holes in pp collisions at a center-of-mass energy of 7TeV is presented. The data sample corresponds to an integrated luminosity of 4.7 fb1 recorded by the CMS experiment at the LHC in 2011. Events with large total transverse energy have been analyzed for the presence of multiple energetic jets, leptons, and photons, which are typical signals of evaporating semiclassical and quantum black holes, and string balls. Agreement with the expected standard model backgrounds, which are dominated by QCD multijet production, has been observed for various combined multiplicities of jets and other reconstructed objects in the final state. Model-independent limits are set on new physics processes producing high-multiplicity, energetic final states. In addition, new model-specific indicative limits are set excluding semiclassical and quantum black holes with masses below 3.8 to 5.3TeV and string balls with masses below 4.6 to 4.8TeV . The analysis has a substantially increased sensitivity compared to previous searches.Search for new physics in events with same-sign dileptons and b-tagged jets in pp collisions at √ s = 7TeV
Journal of High Energy Physics 2012:8 (2012)