79 research outputs found

    Electron-proton elastic scattering at high momentum transfers

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    We report preliminary values of electron-proton elastic scattering measurements at the Stanford Linear Accelerator Center (SLAC) carried out at squared four-momentum transfers q^2 from 0.7 to 25.0 (GeV/c)^2. In the newly accessible region of q^2 above 10 (GeV/c)^2, the principal feature is the continued decrease of the magnetic form factor approximately as 1/q^4

    Elastic Electron-Proton Scattering at Large Four-Momentum Transfer

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    Electron-proton elastic-scattering cross sections have been measured at the Stanford Linear Accelerator Center for four-momentum transfers squared q^2 from 1.0 to 25.0 (GeV/c)^2. The electric (GEp) and magnetic (GMp) form factors of the proton were not separated, since angular distributions were not measured at each q^2. However, values for GMp were derived assuming various relations between GEp and GMp. Several theoretical models for the behavior of the proton magnetic form factor at high values of q^2 are compared with the data

    The Physics of the B Factories

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    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C

    Measurements of Z-boson resonance parameters in e+e- annihilation

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    We have measured the mass of the Z boson to be 91.14±0.12 GeV/c^2, and its width to be 2.42-0.35+0.45 GeV. If we constrain the visible width to its standard-model value, we find the partial width to invisible decay modes to be 0.46±0.10 GeV, corresponding to 2.8±0.6 neutrino species, with a 95%-confidence-level upper limit of 3.9

    First measurements of hadronic decays of the Z boson

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    We have observed hadronic final states produced in the decays of Z bosons. In order to study the parton structure of these events, we compare the distributions in sphericity, thurst, aplanarity, and number of jets to the predictions of several QCD-based models and to data from lower energies. The data and models agree within the present statistical precision

    Studies of jet production rates in e + e − annihilation at E cm =29 GeV

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    Production rates of multijet hadronic final states are studied in e + e − annihilation at 29 GeV center of mass energy. QCD shower model calculations with exact first order matrix element weighting at the first gluon vertex are capable of reproducing the observed multijet event rates over a large range of jet pair masses. The method used to reconstruct jets is well suited for directly comparing experimental jet rates with parton rates calculated in perturbative QCD. Evidence for the energy dependene of α s is obtained by comparing the observed production rates of 3-jet events with results of similar studies performed at higher center of mass energies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47886/1/10052_2005_Article_BF01506527.pd

    Initial measurements of Z-boson resonance parameters in e+e- annihilation

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    We have measured the mass of the Z boson to be 91.11±0.23 GeV/c^2, and its width to be 1.61-0.43+0.60 GeV. If we constrain the visible width to its standard-model value, we find the partial width to invisible decay modes to be 0.62±0.23 GeV, corresponding to 3.8±1.4 neutrino species
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