7,680 research outputs found

    Resolving the Axial Mass Anomaly in neutrino Scattering

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    We present a parametrization of the observed enhancement in the transverse electron quasielastic (QE) response function for nucleons bound in carbon as a function of the square of the four momentum transfer (Q2) in terms of a correction to the magnetic form factors of bound nucleons. The parametrization should also be applicable to the transverse cross section in neutrino scattering. If the transverse enhancement originates from meson exchange currents (MEC), then it is theoretically expected that any enhancement in the longitudinal or axial contributions is small. We present the predictions of the "Transverse Enhancement" model (which is based on electron scattering data only) for the neutrino and anti-neutrino differential and total QE cross sections for nucleons bound in carbon. The 2Q2 dependence of the transverse enhancement is observed to resolve much of the long standing discrepancy ("Axial Mass Anomaly}) in the QE total cross sections and differential distributions between low energy and high energy neutrino experiments on nuclear targets.Comment: 3 pages, 3 Figures, Presented by Arie Bodek at the 19th Particles and Nuclei International Conference, PANIC 2011, MIT, Cambridge, MA July 201

    Vector and Axial Nucleon Form Factors:A Duality Constrained Parameterization

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    We present new parameterizations of vector and axial nucleon form factors. We maintain an excellent descriptions of the form factors at low momentum transfers, where the spatial structure of the nucleon is important, and use the Nachtman scaling variable xi to relate elastic and inelastic form factors and impose quark-hadron duality constraints at high momentum transfers where the quark structure dominates. We use the new vector form factors to re-extract updated values of the axial form factor from neutrino experiments on deuterium. We obtain an updated world average value from neutrino-d and pion electroproduction experiments of M_A = 1.014 +- 0.014 GeV/c2. Our parameterizations are useful in modeling neutrino interactions at low energies (e.g. for neutrino oscillations experiments). The predictions for high momentum transfers can be tested in the next generation electron and neutrino scattering experiments.Comment: 5 pages, 3 figures, to be published in EPJ

    Extraction of Neutrino Flux with the Low ν\nu Method at MiniBooNE Energies

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    We describe the application of the `low-ν\nu' method to the extraction of the neutrino flux at MiniBooNE energies. As an example, we extract the relative energy dependence of the flux from published MiniBooNE quasielastic scattering cross sections with ν<0.2\nu < 0.2 GeV and ν<0.1\nu < 0.1 GeV (here ν\nu is the energy transfer to the target). We find that the flux extracted from the `low-ν\nu' cross sections is consistent with the nominal flux used by MiniBooNE. We fit the MiniBooNE cross sections over the entire kinematic range to various parametrizations of the axial form factor. We find that if the overall normalization of the fit is allowed to float within the normalization errors, the extracted values of the axial vector mass are independent of the flux. Within the Fermi gas model, the Q2Q^2 distribution of the MiniBooNE data is described by a standard dipole form factor with MA=1.41±0.04M_A=1.41\pm0.04 GeV. If nuclear transverse enhancement in the vector form factors is accounted for, the data are best fit with a modified dipole form factor with MA=1.10±0.03M_A=1.10\pm 0.03 GeV.Comment: 5 pages, 6 figures, (presented by A. Bodek at CIPANP 2012, St. Petersburg, FL, June 2012, and at NuFact 2012, Williamsburg, VA, July 2012

    Extraction of the Axial Nucleon Form Factor from Neutrino Experiments on Deuterium

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    We present new parameterizations of vector and axial nucleon form factors. We maintain an excellent descriptions of the form factors at low momentum transfers (Q2Q^2), where the spatial structure of the nucleon is important, and use the Nachtman scaling variable ξ\xi to relate elastic and inelastic form factors and impose quark-hadron duality constraints at high Q2Q^2 where the quark structure dominates. We use the new vector form factors to re-extract updated values of the axial form factor from \numu experiments on deuterium. We obtain an updated world average value from \numud, \numubarH and pion electroproduction experiments of MAM_{A} = 1.014±0.014GeV/c21.014 \pm 0.014 GeV/c^2. Our parameterizations are useful in modeling ν\nu interactions at low energies (e.g. for \numu oscillations experiments). The predictions for high Q2Q^2 can be tested in the next generation electron and \numu scattering experiments.Comment: Presented by A. Bodek at the European Physical Society Meeting, EPS2007, Manchester, England, July 2007, 4 pages, 2 figure

    Ambiguities of neutrino(antineutrino) scattering on the nucleon due to the uncertainties of relevant strangeness form factors

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    Strange quark contributions to neutrino(antineutrino) scattering are investigated on the nucleon level in the quasi-elastic region. The incident energy range between 500 MeV and 1.0 GeV is used for the scattering. All of the physical observable by the scattering are investigated within available experimental and theoretical results for the strangeness form factors of the nucleon. In specific, a newly combined data of parity violating electron scattering and neutrino scattering is exploited. Feasible quantities to be explored for the strangeness contents are discussed for the application to neutrino-nucleus scattering.Comment: 17 pages, 7 figures, submit to J. Phys.

    Fiber R and D for the CMS HCAL

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    This paper documents the fiber R and D for the CMS hadron barrel calorimeter (HCAL). The R and D includes measurements of fiber flexibility, splicing, mirror reflectivity, relative light yield, attenuation length, radiation effects, absolute light yield, and transverse tile uniformity. Schematics of the hardware for each measurement are shown. These studies are done for different diameters and kinds of multiclad fiber.Comment: 23 pages, 30 Figures 89 pages, 41 figures, corresponding author: H. Budd, [email protected]

    Higher Twist, ξw\xi_w Scaling, and Effective LOPDFsLO PDFs for Lepton Scattering in the Few GeV Region

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    We use a new scaling variable ξw\xi_w, and add low Q2Q^2 modifications to GRV98 leading order parton distribution functions such that they can be used to model electron, muon and neutrino inelastic scattering cross sections (and also photoproduction) at both very low and high energies.Comment: 6 pages, 3 figures. To be published in J. Phys. G (Conf. Proceedings) based on two talks by Arie Bodek at the NuFact′02'02 conference, Imperial College, London, England, July 200
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