Search for new physics in high-mass electron-positron events in pp[over] collisions at square root s = 1.96 TeV.
Phys Rev Lett 99:17 (2007) 171802
Abstract:
We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950 GeV/c(2) using 1.3 fb(-1) of pp[over] collision data at square root s = 1.96 TeV collected by the CDF II detector at Fermilab. No significant evidence of such a resonance is observed and we interpret the results to exclude the standard-model-like Z' with a mass below 923 GeV/c(2) and the Randall-Sundrum graviton with a mass below 807 GeV/c(2) for k/M[over](pl) = 0.1, both at the 95% confidence level. Combining with diphoton data excludes the Randall-Sundrum graviton for masses below 889 GeV/c(2) for k/M[over](pl) = 0.1.Searches for direct pair production of supersymmetric top and supersymmetric bottom quarks in pp̄ collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 76:7 (2007)
Abstract:
We search for direct pair production of supersymmetric top quarks and supersymmetric bottom quarks in proton-antiproton collisions at s=1.96TeV, using 295pb-1 of data recorded by the Collider Detector at Fermilab (CDF II) experiment. The supersymmetric top (supersymmetric bottom) quarks are selected by reconstructing their decay into a charm (bottom) quark and a neutralino, which is assumed to be the lightest supersymmetric particle. The signature of such processes is two energetic heavy-flavor jets and missing transverse energy. The number of events that pass our selection for each search process is consistent with the expected standard model background. By comparing our results to the theoretical production cross sections of the supersymmetric top and supersymmetric bottom quarks in the minimal supersymmetric standard model, we exclude, at a 95% confidence level in the frame of that model, a supersymmetric top quark mass up to 132GeV/c2 for a neutralino mass of 48GeV/c2, and a supersymmetric bottom quark mass up to 193GeV/c2 for a neutralino mass of 40GeV/c2. © 2007 The American Physical Society.Measurement of the pp̄→tt̄ production cross section and the top quark mass at s=1.96TeV in the all-hadronic decay mode
Physical Review D - Particles, Fields, Gravitation and Cosmology 76:7 (2007)
Abstract:
We report the measurements of the tt̄ production cross section and of the top quark mass using 1.02fb-1 of pp̄ data collected with the CDF II detector at the Fermilab Tevatron. We select events with six or more jets on which a number of kinematical requirements are imposed by means of a neural network algorithm. At least one of these jets must be identified as initiated by a b-quark candidate by the reconstruction of a secondary vertex. The cross section is measured to be σtt̄=8.3±1.0(stat)-1.5+2.0(syst) ±0.5(lumi)pb, which is consistent with the standard model prediction. The top quark mass of 174.0±2.2(stat)±4.8(syst)GeV/c2 is derived from a likelihood fit incorporating reconstructed mass distributions representative of signal and background. © 2007 The American Physical Society.Search for high-mass diphoton states and limits on randall-sundrum gravitons at CDF
Physical Review Letters 99:17 (2007)
Abstract:
We have performed a search for new particles which decay to two photons using 1.2fb-1 of integrated luminosity from pp̄ collisions at s=1.96TeV collected using the CDF II detector at the Fermilab Tevatron. We find the diphoton mass spectrum to be in agreement with the standard model expectation, and set limits on the cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits for the graviton mass of 230GeV/c2 and 850GeV/c2, at the 95% confidence level, for coupling parameters (k/M̄Pl) of 0.01 and 0.1, respectively. © 2007 The American Physical Society.Search for new physics in high-mass electron-positron events in pp̄ collisions at s=1.96TeV
Physical Review Letters 99:17 (2007)