Rubin-LSST

Abstract:

A search for pair-produced bottom-like quarks in pp collisions at √s=7 TeV is conducted with the CMS experiment at the LHC. The decay b'→tW is considered in this search. The b'b'→t∥W-t̄W+ process can be identified by the distinctive signature of trileptons and same-sign dileptons. With a data sample corresponding to an integrated luminosity of 34 pb-1, no excess above the standard model background predictions is observed and a b' quark with a mass between 255 and 361 GeV/c2 is excluded at the 95% confidence level. © 2011 CERN.

Abstract:

A search for groups of collimated muons is performed using a data sample collected by the CMS experiment at the LHC, at a centre-of-mass energy of 7 TeV, and corresponding to an integrated luminosity of 35 pb-1. The analysis searches for production of new low-mass states decaying into pairs of muons and is designed to achieve high sensitivity to a broad range of models predicting leptonic jet signatures. With no excess observed over the background expectation, upper limits on the production cross section times branching fraction times acceptance are set, ranging from 0.1 to 0.5 pb at the 95% CL depending on event topology. In addition, the results are interpreted in several benchmark models in the context of supersymmetry with a new light dark sector exploring previously inaccessible parameter space.

Abstract:

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 pb-1 collected in proton-proton collisions at √s = 7TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets.

Abstract:

A search for narrow resonances with a mass of at least 1 TeV in the dijet mass spectrum is performed using pp collisions at s=7TeV corresponding to an integrated luminosity of 1 fb-1, collected by the CMS experiment at the LHC. No resonances are observed. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, and gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances with mass less than 4.00 TeV, E6 diquarks with mass less than 3.52 TeV, excited quarks with mass less than 2.49 TeV, axigluons and colorons with mass less than 2.47 TeV, and W' bosons with mass less than 1.51 TeV. These results extend previous exclusions from the dijet mass search technique. © 2011 CERN.

Abstract:

A search for squarks and gluinos in final states containing jets, missing transverse momentum and no electrons or muons is presented. The data were recorded by the ATLAS experiment in √s=7 TeV proton-proton collisions at the Large Hadron Collider. No excess above the Standard Model background expectation was observed in 35 pb-1 of analysed data. Gluino masses below 500 GeV are excluded at the 95% confidence level in simplified models containing only squarks of the first two generations, a gluino octet and a massless neutralino. The exclusion increases to 870 GeV for equal mass squarks and gluinos. In MSUGRA/CMSSM models with tanβ=3, A0=0 and μ>0, squarks and gluinos of equal mass are excluded below 775 GeV. These are the most stringent limits to date. © 2011 CERN.