Top quark mass measurement in the tt̄ all hadronic channel using a matrix element technique in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:7 (2009)
Abstract:
We present a measurement of the top quark mass in the all hadronic channel (tt̄→bb̄q1q̄2q3q̄4) using 943pb-1 of pp̄ collisions at s=1.96TeV collected at the CDF II detector at Fermilab (CDF). We apply the standard model production and decay matrix element (ME) to tt̄ candidate events. We calculate per-event probability densities according to the ME calculation and construct template models of signal and background. The scale of the jet energy is calibrated using additional templates formed with the invariant mass of pairs of jets. These templates form an overall likelihood function that depends on the top quark mass and on the jet energy scale (JES). We estimate both by maximizing this function. Given 72 observed events, we measure a top quark mass of 171.1±3.7(stat+JES)±2.1(syst)GeV/c2. The combined uncertainty on the top quark mass is 4.3GeV/c2. © 2009 The American Physical Society.Inclusive search for squark and Gluino production in pp̄ collisions at s=1.96TeV
Physical Review Letters 102:12 (2009)
Abstract:
We report on a search for inclusive production of squarks and gluinos in pp̄ collisions at s=1.96TeV, in events with large missing transverse energy and multiple jets of hadrons in the final state. The study uses a CDF Run II data sample corresponding to 2fb-1 of integrated luminosity. The data are in good agreement with the standard model predictions, giving no evidence for any squark or gluino component. In an R-parity conserving minimal supergravity scenario with A0=0, μ<0, and tan β=5, 95 C.L. upper limits on the production cross sections in the range between 0.1 and 1 pb are obtained, depending on the squark and gluino masses considered. For gluino masses below 280GeV/c2, arbitrarily large squark masses are excluded at the 95 C.L., while for mass degenerate gluinos and squarks, masses below 392GeV/c2 are excluded at the 95 C.L. © 2009 The American Physical Society.Measurement of resonance parameters of orbitally excited narrow B0 mesons.
Phys Rev Lett 102:10 (2009) 102003
Abstract:
We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width.Search for high-mass resonances decaying to dimuons at CDF.
Phys Rev Lett 102:9 (2009) 091805
Abstract:
We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb(-1) collected in pp[over ] collisions at sqrt[s]=1.96 TeV by the CDF II detector at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 95% confidence level upper limits on sigmaBR(pp-->X-->micromicro), where X is a boson with spin-0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, Z' bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.Measurement of cross sections for b jet production in events with a Z boson in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:5 (2009)