253 research outputs found

    Measurement of the ratios of branching fractions B (B-s(0)-\u3e D-s(-) pi(+) pi(+) pi(-))/B(B-0 -\u3e D- pi(+) pi(+) pi(-)) and B(B-s(0) -\u3e D-s(-) pi(+))/B(B-0 -\u3e D- pi(+))

    Get PDF
    Using 355 pb(-1) of data collected by the CDF II detector in p (p) over bar at collisions at root s = 1.96 TeV at the Fermilab Tevatron, we study the fully reconstructed hadronic decays B-(s)(0) -\u3e D-(s)(-)pi(+) and B-(s)(0) -\u3e D-(s)(-) pi(+)pi(+)pi(-). We present the first measurement of the ratio of branching fractions B(B-s(0) -\u3e D-s(-) pi(+)pi(+)pi(-))/B(B-0 -\u3e D-s(-) pi(+)pi(+)pi(-)) = 1.05 +/- 0.10(stat) +/- 0.22(syst). We also update our measurement of B(B-s(0) -\u3e D-s(-)pi(+))/B(B-0 -\u3e D-pi(+)) to 1.13 +/- 0.08(stat) +/- 0.23(syst), improving the statistical uncertainty by more than a factor of 2. We find B(B-s(0) -\u3e D-s(-)pi(+)) = [3.8 +/- 0.3(stat) +/- 1.3(syst)] x 10(-3) and B(B-s(0) -\u3e D-s(-) pi(+)pi(+)pi(-)) = [8.4 +/- 0.8 (stat) +/- 3.2(syst)] x 10(-3)

    Measurement of inclusive jet cross sections in Z/gamma*(-\u3e e(+)e(-))+jets production in p(p)over-bar collisions at root s=1.96 TeV

    Get PDF
    Inclusive jet cross sections in Z/gamma* events, with Z/gamma* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in p (p) over bar collisions at root s=1.96 TeV with the upgraded Collider Detector at Fermilab in run II, based on an integrated luminosity of 1.7 fb(-1). The measurements cover the rapidity region |y(jet)|\u3c2.1 and the transverse momentum range p(T)(jet)\u3e30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections

    Selection of the silicon sensor thickness for the Phase-2 upgrade of the CMS Outer Tracker

    Get PDF
    During the operation of the CMS experiment at the High-Luminosity LHC the silicon sensors of the Phase-2 Outer Tracker will be exposed to radiation levels that could potentially deteriorate their performance. Previous studies had determined that planar float zone silicon with n-doped strips on a p-doped substrate was preferred over p-doped strips on an n-doped substrate. The last step in evaluating the optimal design for the mass production of about 200 m2^{2} of silicon sensors was to compare sensors of baseline thickness (about 300 μm) to thinned sensors (about 240 μm), which promised several benefits at high radiation levels because of the higher electric fields at the same bias voltage. This study provides a direct comparison of these two thicknesses in terms of sensor characteristics as well as charge collection and hit efficiency for fluences up to 1.5 × 1015^{15} neq_{eq}/cm2^{2}. The measurement results demonstrate that sensors with about 300 μm thickness will ensure excellent tracking performance even at the highest considered fluence levels expected for the Phase-2 Outer Tracker

    Test beam performance of a CBC3-based mini-module for the Phase-2 CMS Outer Tracker before and after neutron irradiation

    Get PDF
    The Large Hadron Collider (LHC) at CERN will undergo major upgrades to increase the instantaneous luminosity up to 5–7.5×1034^{34} cm2^{-2}s1^{-1}. This High Luminosity upgrade of the LHC (HL-LHC) will deliver a total of 3000–4000 fb-1 of proton-proton collisions at a center-of-mass energy of 13–14 TeV. To cope with these challenging environmental conditions, the strip tracker of the CMS experiment will be upgraded using modules with two closely-spaced silicon sensors to provide information to include tracking in the Level-1 trigger selection. This paper describes the performance, in a test beam experiment, of the first prototype module based on the final version of the CMS Binary Chip front-end ASIC before and after the module was irradiated with neutrons. Results demonstrate that the prototype module satisfies the requirements, providing efficient tracking information, after being irradiated with a total fluence comparable to the one expected through the lifetime of the experiment

    First measurement of the ratio of branching fractions B(Lambda(0)(b) -\u3e Lambda(+)(c) mu(-) (nu)over-bar(mu))/B(Lambda(0)(b) -\u3e Lambda(+)(c) pi(-))

    Get PDF

    Search for narrow resonances in dilepton mass spectra in proton-proton collisions at root s=13 TeV and combination with 8 TeV data

    Get PDF
    Peer reviewe

    Multiplicity and rapidity dependence of strange hadron production in pp, pPb, and PbPb collisions at the LHC

    Get PDF
    Peer reviewe

    Search for heavy gauge W ' bosons in events with an energetic lepton and large missing transverse momentum at root s=13TeV

    Get PDF
    Peer reviewe

    Event activity dependence of Y (nS) production in √sNN = 5.02 TeV pPb and √s = 2.76 TeV pp collisions

    Get PDF
    Peer reviewe

    Combined search for anomalous pseudoscalar HW couplings in VH(H -> b(b)over-bar) production and H -> VV decay

    Get PDF
    Peer reviewe
    corecore