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)
Abstract:
We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950GeV/c2 using 1.3fb-1 of pp̄ collision data at s=1.96TeV 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 923GeV/c2 and the Randall-Sundrum graviton with a mass below 807GeV/c2 for k/M̄pl=0.1, both at the 95% confidence level. Combining with diphoton data excludes the Randall-Sundrum graviton for masses below 889GeV/c2 for k/M̄pl=0.1. © 2007 The American Physical Society.Measurement of the pp̄→tt̄+X production cross section at s=1.96TeV in the fully hadronic decay channel
Physical Review D - Particles, Fields, Gravitation and Cosmology 76:7 (2007)
Abstract:
A measurement of the top quark pair production cross section in proton antiproton collisions at an interaction energy of s=1.96TeV is presented. This analysis uses 405±25pb-1 of data collected with the D0 detector at the Fermilab Tevatron Collider. Fully hadronic tt̄ decays with final states of six or more jets are separated from the multijet background using secondary vertex tagging and a neural network. The tt̄ cross section is measured as σtt̄=4.5-1.9+2.0(stat)-1.1+1.4(syst)±0.3(lumi)pb for a top quark mass of mt=175GeV/c2. © 2007 The American Physical Society.Search for new particles leading to Z+jets final states in pp̄ collisions at s=1.96TeV
Physical Review D Particles Fields Gravitation and Cosmology 76:7 (2007)
Abstract:
We present the results of a search for new particles that lead to a Z boson plus jets in pp̄ collisions at s=1.96TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06fb-1 collected using Z boson decays to ee and μμ is used. We describe a completely data-based method to predict the dominant background from standard model Z+jet events. This method can be similarly applied to other analyses requiring background predictions in multijet environments, as shown when validating the method by predicting the background from W+jets in tt̄ production. No significant excess above the background prediction is observed, and a limit is set using a fourth generation quark model to quantify the acceptance. Assuming BR(b′→bZ)=100% and using a leading-order calculation of the b′ cross section, b′ quark masses below 268GeV/c2 are excluded at 95% confidence level. © 2007 The American Physical Society.Measurement of neutrino velocity with the MINOS detectors and NuMI neutrino beam
Physical Review D Particles Fields Gravitation and Cosmology 76:7 (2007)