Measurement of the differential cross section for the production of an isolated photon with associated jet in p over(p, ̄) collisions at sqrt(s) = 1.96 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 666:5 (2008) 435-445
Abstract:
The process p over(p, ̄) → γ + jet + X is studied using 1.0 fb-1 of data collected by the D0 detector at the Fermilab Tevatron p over(p, ̄) collider at a center-of-mass energy sqrt(s) = 1.96 TeV. Photons are reconstructed in the central rapidity region | yγ | < 1.0 with transverse momenta in the range 30 < pTγ < 400 GeV while jets are reconstructed in either the central | yjet | < 0.8 or forward 1.5 < | yjet | < 2.5 rapidity intervals with pTjet > 15 GeV. The differential cross section d3 σ / d pTγ d yγ d yjet is measured as a function of pTγ in four regions, differing by the relative orientations of the photon and the jet in rapidity. Ratios between the differential cross sections in each region are also presented. Next-to-leading order QCD predictions using different parameterizations of parton distribution functions and theoretical scale choices are compared to the data. The predictions do not simultaneously describe the measured normalization and pTγ dependence of the cross section in the four measured regions.Measurement of neutrino oscillations with the MINOS detectors in the NuMI beam.
Physical review letters 101:13 (2008) 131802
Abstract:
This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Deltam2| = (2.43+/-0.13) x 10(-3) eV2 (68% C.L.) and mixing angle sin2(2theta) > 0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively.Publisher’s Note: Search for Pair Production of Scalar Top Quarks Decaying to a τ Lepton and a b Quark in pp¯ Collisions at s=1.96 TeV [Phys. Rev. Lett. 101, 071802 (2008)]
Physical Review Letters American Physical Society (APS) 101:8 (2008) 089901
Search for heavy, long-lived neutralinos that decay to photons at CDF II using photon timing
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:3 (2008)
Abstract:
We present the results of the first hadron collider search for heavy, long-lived neutralinos that decay via χ10→γG in gauge-mediated supersymmetry breaking models. Using an integrated luminosity of 570±34pb-1 of pp̄ collisions at s=1.96TeV, we select γ+jet+missing transverse energy candidate events based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed on the CDF II detector. We find 2 events, consistent with the background estimate of 1.3±0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross section limits and place the world-best 95% C.L. lower limit on the χ 10 mass of 101GeV/c2 at τχ 10=5ns. © 2008 The American Physical Society.Erratum: Search for pair production of scalar top quarks decaying to a τ Lepton and a b quark in pp̄ collisions at s=1.96TeV (Physical Review Letters (2008) 101 (071802))
Physical Review Letters 101:8 (2008)