Search for new particles decaying into dijets in proton-antiproton collisions at s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 79:11 (2009)
Abstract:
We present a search for new particles which produce narrow two-jet (dijet) resonances using proton-antiproton collision data corresponding to an integrated luminosity of 1.13fb-1 collected with the CDFA II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y| <1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet techni-ρ, W′, and Z′. © 2009 The American Physical Society.First measurement of the tt[over ] differential cross section dsigma/dM_{tt[over ]} in pp[over ] collisions at sqrt[s]=1.96 TeV.
Physical review letters 102:22 (2009) 222003
Abstract:
We present a measurement of the tt[over ] differential cross section with respect to the tt[over ] invariant mass, dsigma/dM_{tt[over ]}, in pp[over ] collisions at sqrt[s]=1.96 TeV using an integrated luminosity of 2.7 fb;{-1} collected by the CDF II experiment. The tt[over ] invariant mass spectrum is sensitive to a variety of exotic particles decaying into tt[over ] pairs. The result is consistent with the standard model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions.Observation of exclusive charmonium production and gammagamma --> micro;{+}micro;{-} in pp[over] collisions at sqrt[s] = 1.96 TeV.
Physical review letters 102:24 (2009) 242001
Abstract:
In CDF we have observed the reactions p + p[over] --> p + X + p[over], with X being a centrally produced J/psi, psi(2S), or chi_{c0}, and gammagamma-->micro;{+}micro;{-} in pp[over] collisions at sqrt[s] = 1.96 TeV. The event signature requires two oppositely charged central muons, and either no other particles or one additional photon detected. Exclusive vector meson production is as expected for elastic photoproduction, gamma + p --> J/psi(psi(2S)) + p, observed here for the first time in hadron-hadron collisions. We also observe exclusive chi_{c0} --> J/psi + gamma. The cross sections dsigma/dy|_{y = 0} for J/psi, psi(2S), and chi_{c0} are 3.92 +/- 0.25(stat) +/- 0.52(syst) nb, 0.53 +/- 0.09(stat) +/- 0.10(syst) nb, and 76 +/- 10(stat) +/- 10(syst) nb, respectively, and the continuum is consistent with QED. We put an upper limit on the cross section for Odderon exchange in exclusive J/psi production.Search for exclusive Z-boson production and observation of high-mass pp[over ]-->pgammagammap[over ]-->pl;{+}l;{-}p[over ] events in pp[over ] collisions at sqrt[s]=1.96 TeV.
Physical review letters 102:22 (2009) 222002
Abstract:
This Letter presents a search for exclusive Z boson production in proton-antiproton collisions at sqrt[s]=1.96 TeV, using the CDF II detector. No exclusive Z-->l;{+}l;{-} candidates are observed and the first upper limit on the exclusive Z cross section in hadron collisions is found to be sigma_{excl}(Z)<0.96 pb at 95% confidence level. In addition, eight candidate exclusive dilepton events from the process pp[over ]-->pgammagammap[over ]-->pl;{+}l;{-}p[over ] are observed, and a measurement of the cross section for M_{ll}>40 GeV/c;{2} and |eta_{l}|<4 is found to be sigma=0.24_{-0.10};{+0.13} pb, which is consistent with the standard model prediction.Search for the decays B(s)0→e+μ- and B(s)0→e+e- in CDF run II
Physical Review Letters 102:20 (2009)