Rubin-LSST

Abstract:

We present a new measurement of the inclusive forward-backward tt̄ production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3fb -1 of pp̄ collisions at √s=1.96TeV, recorded with the CDF-II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the tt̄ rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and t̄. In the tt̄ rest frame, the asymmetry is observed to increase with the tt̄ rapidity difference, Δy, and with the invariant mass M tt̄ of the tt̄ system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large Δy and Mtt̄. For Mtt̄?450GeV/c2, the parton-level asymmetry in the tt̄ rest frame is Att̄=0.475±0.114 compared to a next-to-leading order QCD prediction of 0.088±0.013. © 2011 American Physical Society.

Abstract:

A search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 36pb-1 recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent new bounds in the MSSM parameter space. © 2011 American Physical Society.

Abstract:

We present a measurement of the top quark mass in the lepton+jets and dilepton channels of tt̄ decays using the data sample corresponding to an integrated luminosity of 5.6fb-1 of pp̄ collisions at Tevatron with √s=1.96TeV, collected with the CDF II detector. We construct templates of two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the W decays in the lepton+jets channel, and a reconstructed top quark mass and mT2, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the lepton+jets and dilepton channels to the data yields a measured top quark mass of Mtop=172.1±1.1(stat)±0. 9(syst)GeV/c2. © 2011 American Physical Society.

Abstract:

We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.