1,645 research outputs found
Superscaling and neutral current quasielastic neutrino-nucleus scattering
The superscaling approach is applied to studies of neutral current neutrino
reactions in the quasielastic regime. Using input from scaling analyses of
electron scattering data, predictions for high-energy neutrino and antineutrino
cross sections are given and compared with results obtained using the
relativistic Fermi gas model. The influence of strangeness content inside the
nucleons in the nucleus is also explored.Comment: 28 pages, 8 figures, accepted for publication in Phys.Rev.
Using Electron Scattering Superscaling to predict Charge-changing Neutrino Cross Sections in Nuclei
Superscaling analyses of few-GeV inclusive electron scattering from nuclei
are extended to include not only quasielastic processes, but now also into the
region where -excitation dominates. It is shown that, with reasonable
assumptions about the basic nuclear scaling function extracted from data and
information from other studies of the relative roles played by correlation and
MEC effects, the residual strength in the resonance region can be accounted for
through an extended scaling analysis. One observes scaling upon assuming that
the elementary cross section by which one divides the residual to obtain a new
scaling function is dominated by the transition and employing a
new scaling variable which is suited to the resonance region. This yields a
good representation of the electromagnetic response in both the quasielastic
and regions. The scaling approach is then inverted and predictions are
made for charge-changing neutrino reactions at energies of a few GeV, with
focus placed on nuclei which are relevant for neutrino oscillation
measurements. For this a relativistic treatment of the required weak
interaction vector and axial-vector currents for both quasielastic and
-excitation processes is presented.Comment: 42 pages, 9 figures, accepted for publication in Physical Review
Quasielastic Charged Current Neutrino-nucleus Scattering
We provide integrated cross sections for quasielastic charged-current
neutrino-nucleus scattering. Results evaluated using the phenomenological
scaling function extracted from the analysis of experimental data are
compared with those obtained within the framework of the relativistic impulse
approximation. We show that very reasonable agreement is reached when a
description of final-state interactions based on the relativistic mean field is
included. This is consistent with previous studies of differential cross
sections which are in accord with the universality property of the superscaling
function.Comment: 5 pages, 3 figures, to be published in Phys. Rev. Let
Analysis of Meson Exchange and Isobar Currents in (e,e'p) Reactions from O-16
An analysis of the effects of meson exchange and isobar currents in exclusive
(e,e'p) processes from O-16 under quasi-free kinematics is presented. A model
that has probed its feasibility for inclusive quasi-elastic (e,e') processes is
considered. Sensitivity to final state interactions between the outgoing proton
and the residual nucleus is discussed by comparing the results obtained with
phenomenological optical potentials and a continuum nuclear shell-model
calculation. The contribution of the meson-exchange and isobar currents to the
response functions is evaluated and compared to previous calculations, which
differ notably from our results. These two-body contributions cannot solve the
puzzle of the simultaneous description of the different responses
experimentally separated. Copyright 1999 by The American Physical SocietyComment: 5 pages, plus 3 PS figures. To be published in Phys. Rev. C Updated
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Pionic correlations and meson-exchange currents in two-particle emission induced by electron scattering
Two-particle two-hole contributions to electromagnetic response functions are
computed in a fully relativistic Fermi gas model. All one-pion exchange
diagrams that contribute to the scattering amplitude in perturbation theory are
considered, including terms for pionic correlations and meson-exchange currents
(MEC). The pionic correlation terms diverge in an infinite system and thus are
regularized by modification of the nucleon propagator in the medium to take
into account the finite size of the nucleus. The pionic correlation
contributions are found to be of the same order of magnitude as the MEC.Comment: 14 pages, 15 figure
Nuclear effects in neutrino-nucleus interactions
An accurate description of the nuclear response functions for neutrino
scattering in the Gev region is essential for the interpretation of present and
future neutrino oscillation experiments. Due to the close similarity of
electromagnetic and weak scattering processes, we will review the status of the
scaling approach and of relativistic modeling for the inclusive electron
scattering response functions in the quasielastic and -resonance
regions. In particular, recent studies have been focused on scaling violations
and the degree to which these imply modifications of existing predictions for
neutrino reactions. We will discuss sources and magnitude of such violations,
emphasizing similarities and differences between electron and neutrino
reactions.Comment: 7 pages, 5 figures, Proceeding of the XVIII International School on
Nuclear Physics, Neutron Physics and Applications, September 21 - 27, 2009
Varna, Bulgari
Relativistic Models for Quasi-Elastic Neutrino-Nucleus Scattering
Two relativistic approaches to charged-current quasielastic neutrino-nucleus
scattering are illustrated and compared: one is phenomenological and based on
the superscaling behavior of electron scattering data and the other relies on
the microscopic description of nuclear dynamics in relativistic mean field
theory. The role of meson exchange currents in the two-particle two-hole sector
is explored. The predictions of the models for differential and total cross
sections are presented and compared with the MiniBooNE data.Comment: 3 pages, 3 figures, Proceedings of PANIC 2011, MIT, Cambridge, MA,
July 201
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