Measurement of Zγ production in pp̄ collisions at √s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 82:3 (2010)
Abstract:
The production rate and kinematics of photons produced in association with Z bosons are studied using 2fb-1 of pp̄ collision data collected at the Collider Detector at Fermilab. The cross section for pp̄→"+-γ+X (where the leptons " are either muons or electrons with dilepton mass M>40GeV/c2, and where the photon has transverse energy ETγ>7GeV and is well separated from the leptons) is 4.6±0.2(stat)±0.3(syst)±0.3(lum)pb, which is consistent with standard model expectations. We use the photon ET distribution from Zγ events where the Z has decayed to μ+μ -, e+e-, or νν̄ to set limits on anomalous (non standard model) trilinear couplings between photons and Z bosons. © 2010 The American Physical Society.Search for the production of scalar bottom quarks in pp collisions at square root(s) = 1.96 TeV.
Phys Rev Lett 105:8 (2010) 081802
Abstract:
We report on a search for direct scalar bottom quark (sbottom) pair production in pp collisions at square root(s) = 1.96 TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65 fb(-1) of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70 GeV/c2, sbottom masses up to 230 GeV/c2 are excluded at 95% confidence level.Search for the production of scalar bottom quarks in pp̄ collisions at √s=1.96TeV
Physical Review Letters 105:8 (2010)
Abstract:
We report on a search for direct scalar bottom quark (sbottom) pair production in pp̄ collisions at √s=1.96TeV, in events with large missing transverse energy and two jets of hadrons in the final state, where at least one of the jets is required to be identified as originating from a b quark. The study uses a collider detector at Fermilab Run II data sample corresponding to 2.65fb-1 of integrated luminosity. The data are in agreement with the standard model. In an R-parity conserving minimal supersymmetric scenario, and assuming that the sbottom decays exclusively into a bottom quark and a neutralino, 95% confidence-level upper limits on the sbottom pair production cross section of 0.1 pb are obtained. For neutralino masses below 70GeV/c2, sbottom masses up to 230GeV/c2 are excluded at 95% confidence level. © 2010 The American Physical Society.Combined measurement and QCD analysis of the inclusive e ±p scattering cross sections at HERA
Journal of High Energy Physics 2010:1 (2010)
Abstract:
A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e±p scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q2, and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.Studying the underlying event in Drell-Yan and high transverse momentum jet production at the Tevatron
Physical Review D - Particles, Fields, Gravitation and Cosmology 82:3 (2010)