Measurement of isolated photon production in deep inelastic ep scattering
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 687:1 (2010) 16-25
Abstract:
Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320 pb - 1. Measurements were made in the isolated-photon transverse-energy and pseudorapidity ranges 4 < E Tγ < 15 GeV and - 0.7 < η γ < 0.9 for exchanged photon virtualities, Q 2, in the range 10 < Q 2 < 350 GeV 2 and for invariant masses of the hadronic system W X > 5 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q 2, x, E Tγ and η γ. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range. © 2010 Elsevier B.V.First measurement of the b-Jet cross section in events with a W boson in pp̄ collisions at √s=1.96TeV
Physical Review Letters 104:13 (2010)
Abstract:
The cross section for jets from b quarks produced with a W boson has been measured in pp̄ collision data from 1.9fb-1 of integrated luminosity recorded by the CDF II detector at the Tevatron. The W+b-jets process poses a significant background in measurements of top quark production and prominent searches for the Higgs boson. We measure a b-jet cross section of 2.74±0.27(stat)±0.42(syst)pb in association with a single flavor of leptonic W boson decay over a limited kinematic phase space. This measured result cannot be accommodated in several available theoretical predictions. © 2010 The American Physical Society.First measurement of the b-jet cross section in events with a W boson in pp collisions at square root(s) = 1.96 TeV.
Phys Rev Lett 104:13 (2010) 131801
Abstract:
The cross section for jets from b quarks produced with a W boson has been measured in pp collision data from 1.9 fb(-1) of integrated luminosity recorded by the CDF II detector at the Tevatron. The W+b-jets process poses a significant background in measurements of top quark production and prominent searches for the Higgs boson. We measure a b-jet cross section of 2.74+/-0.27(stat)+/-0.42(syst) pb in association with a single flavor of leptonic W boson decay over a limited kinematic phase space. This measured result cannot be accommodated in several available theoretical predictions.A posteriori inclusion of parton density functions in NLO QCD final-state calculations at hadron colliders: The APPLGRID project
European Physical Journal C 66:3 (2010) 503-524
Abstract:
A method to facilitate the consistent inclusion of cross-section measurements based on complex final-states from HERA, TEVATRON and the LHC in proton parton density function (PDF) fits has been developed. This can be used to increase the sensitivity of LHC data to deviations from Standard Model predictions. The method stores perturbative coefficients of NLO QCD calculations of final-state observables measured in hadron colliders in look-up tables. This allows the a posteriori inclusion of parton density functions (PDFs), and of the strong coupling, as well as the a posteriori variation of the renormalisation and factorisation scales in cross-section calculations. The main novelties in comparison to original work on the subject are the use of higher-order interpolation of Lagrangian form, which substantially improves the trade-off between accuracy and memory use, and a CPU and computer memory optimised way to construct and store the look-up table using modern software tools. It is demonstrated that a sufficient accuracy on the cross-section calculation can be achieved with reasonably small look-up table size by using the examples of jet production and electro-weak boson (Z, W) production in proton-proton collisions at a center-of-mass energy of 14 TeV at the LHC. The use of this technique in PDF fitting is demonstrated in a PDF-fit to HERA data and simulated LHC jet cross-sections as well as in a study of the jet cross-section uncertainties at various centre-of-mass energies. © Springer-Verlag / Società Italiana di Fisica 2010.Measurement of the top quark mass and pp̄→tt̄ cross section in the all-hadronic mode with the CDF II detector
Physical Review D - Particles, Fields, Gravitation and Cosmology 81:5 (2010)