1,655 research outputs found

    Measurement of the Top Quark Mass with a Matrix Element Method in the Lepton Plus Jets Channel at CDF

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    We present a measurement of the mass of the top quark from ppbar collisions at 1.96 TeV observed with the Collider Detector at Fermilab (CDF) at the Fermilab Tevatron Run II. The events have the decay signature of ppbar to ttbar in the lepton plus jets channel in which at least one jet is identified as coming from a secondary vertex and therefore a b-hadron. The largest systematic uncertainty, the jet energy scale (JES), is convoluted with the statistical error using an in-situ measurement of the hadronic W boson mass. We calculate a likelihood for each event using leading-order ttbar and W+jets cross-sections and parameterized parton showering. The final measured top quark mass and JES systematic is extracted from a joint likelihood of the product of individual event likelihoods. From 118 events observed in 680 pb-1 of data, we measure a top quark mass of 174.09 +- 2.54 (stat+JES) +- 1.35 (syst) GeV/c2.Comment: Proceedings for the 41st Rencontres de Moriond, EWK, March 11 - 28, 2006. 4 pages, 1 figur

    Henri Temianka (Concert Programs)

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    This collection contains material pertaining to the life, career, and activities of Henri Temianka, violin virtuoso, conductor, music teacher, and author. Materials include correspondence, concert programs and flyers, music scores, photographs, and books.https://digitalcommons.chapman.edu/temianka_ephemera/1052/thumbnail.jp

    Left-Handed W Bosons at the LHC

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    The production of W bosons in association with jets is an important background to new physics at the LHC. Events in which the W carries large transverse momentum and decays leptonically lead to large missing energy and are of particular importance. We show that the left-handed nature of the W coupling, combined with valence quark domination at a pp machine, leads to a large left-handed polarization for both W^+ and W^- bosons at large transverse momenta. The polarization fractions are very stable with respect to QCD corrections. The leptonic decay of the W bosons translates the common left-handed polarization into a strong asymmetry in transverse momentum distributions between positrons and electrons, and between neutrinos and anti-neutrinos (missing transverse energy). Such asymmetries may provide an effective experimental handle on separating W + jets from top quark production, which exhibits very little asymmetry due to C invariance, and from various types of new physics.Comment: 32 pages, revtex, 17 figures, 3 tables, v2 minor corrections to ME+PS results, no changes to conclusions, added reference

    Bootstrapping Multi-Parton Loop Amplitudes in QCD

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    We present a new method for computing complete one-loop amplitudes, including their rational parts, in non-supersymmetric gauge theory. This method merges the unitarity method with on-shell recursion relations. It systematizes a unitarity-factorization bootstrap approach previously applied by the authors to the one-loop amplitudes required for next-to-leading order QCD corrections to the processes e^+e^- -> Z,\gamma^* -> 4 jets and pp -> W + 2 jets. We illustrate the method by reproducing the one-loop color-ordered five-gluon helicity amplitudes in QCD that interfere with the tree amplitude, namely A_{5;1}(1^-,2^-,3^+,4^+,5^+) and A_{5;1}(1^-,2^+,3^-,4^+,5^+). Then we describe the construction of the six- and seven-gluon amplitudes with two adjacent negative-helicity gluons, A_{6;1}(1^-,2^-,3^+,4^+,5^+,6^+) and A_{7;1}(1^-,2^-,3^+,4^+,5^+,6^+,7^+), which uses the previously-computed logarithmic parts of the amplitudes as input. We present a compact expression for the six-gluon amplitude. No loop integrals are required to obtain the rational parts.Comment: 43 pages, 8 figures, RevTeX, v2-v4 clarifications and minor correction

    Next-to-Leading Order W + 5-Jet Production at the LHC

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    We present next-to-leading order QCD predictions for the total cross section and for a comprehensive set of transverse-momentum distributions in W + 5-jet production at the Large Hadron Collider. We neglect the small contributions from subleading-color virtual terms, top quarks and some terms containing four quark pairs. We also present ratios of total cross sections, and use them to obtain an extrapolation formula to an even larger number of jets. We include the decay of the WW boson into leptons. This is the first such computation with six final-state vector bosons or jets. We use BlackHat together with SHERPA to carry out the computation.Comment: RevTex, 27 pages, 7 figures, v2 minor corrections and corrected reference

    Adoption and Usage of Online Services in the Presence of Complementary Offline Services: Retail Banking

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    The availability and variety of online services has increased dramatically in recent years. Many questions remain, however, regarding patterns of online service use, consumer preferences when using online services, and how consumers substitute between equivalent online and offline services. Using an extensive data set of consumer adoption and usage of the online banking service of a major German bank, this paper analyzes consumers' adoption and usage of online banking over the period August 2001 to July 2003, including the effect of demographics and branch banking on usage of online banking. We also examine the relationship between Internet availability and channel choice as well as usage. Finally, we analyze the effect of channel usage on customer level and product-specific revenues earned by the bank and derive revenue implications of online banking

    Consumer-Producer API for Named Data Networking

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    ABSTRACT This paper presents a new network programming interface to NDN communication protocols and architectural modules. This new API is made of (1) a consumer context which associates a name prefix with consumer-specific data fetch parameters controlling Interest transmission and Data packet processing, and (2) a producer context which associates a name prefix with producer-specific data transfer parameters controlling Interests demultiplexing and Data packet production. Both API contexts are extensible to new functionalities once they are identified
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