Nuclear charge and magnetization density distribution parameters from elastic electron scattering

GENIE [1] is a new neutrino event generator for the experimental neutrino physics community. The goal of the project is to develop a ‘canonical’ neutrino interaction physics Monte Carlo whose validity extends to all nuclear targets and neutrino flavors from MeV to PeV energy scales. Currently, emphasis is on the few-GeV energy range, the challenging boundary between the non-perturbative and perturbative regimes, which is relevant for the current and near future long-baseline precision neutrino experiments using accelerator-made beams. The design of the package addresses many challenges unique to neutrino simulations and supports the full life-cycle of simulation and generator-related analysis tasks. GENIE is a large-scale software system, consisting of ∼ 120 000 lines of C ++ code, featuring a modern object-oriented design and extensively validated physics content. The first official physics release of GENIE was made available in August 2007, and at the time of the writing of this article, the latest available version was v2.4.4.

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The GENIE * Neutrino Monte Carlo Generator

Photo pair productions of electrons, muons, and heavy leptons and bremsstrahlung of electrons and muons are reviewed. Atomic and nuclear form factors necessary for these calculations are discussed. Straggling of electrons in matter and other effects due to finite target thickness are considered. Tables of radiation lengths of all materials and the energy dependence of photon absorption coefficients of many materials are presented. Problems associated with production of particles by photon and electron beams are also discussed.

/pdf/pair-production-and-bremsstrahlung-of-charged-leptons-s67iyorj08.pdf

Pair Production and Bremsstrahlung of Charged Leptons

Energy levels of A = 21−44 nuclei (V)

▪ Abstract Accurate quantum Monte Carlo calculations of ground states and low-lying excited states of light p-shell nuclei are now possible for realistic nuclear Hamiltonians that fit nucleon-nucleon scattering data. Results for more than 30 different (Jπ;T) states, plus isobaric analogs, in A ≤ 8 nuclei have been obtained with an excellent reproduction of the experimental energy spectrum. These microscopic calculations show that nuclear structure, including both single-particle and clustering aspects, can be explained starting from elementary two- and three-nucleon interactions. Various density and momentum distributions, electromagnetic form factors, and spectroscopic factors have also been computed, as well as electroweak capture reactions of astrophysical interest.

Quantum Monte Carlo Calculations of Light Nuclei

The cross sections for quasielastic electron scattering from nine target nuclei from lithium to lead have been measured for an electron incident energy of 500 MeV and a scattering angle of 60\ifmmode^\circ\else\textdegree\fi{}. The data are interpreted in terms of a Fermi gas model, yielding the nuclear Fermi momentum as a function of atomic number. The Fermi momentum increases from lithium to calcium and remains roughly constant at about 260 $\frac{\mathrm{MeV}}{c}$ from nickel to lead.

Nuclear Fermi momenta from quasielastic electron scattering

Deep-inelastic electron scattering from /sup 40/Ca, /sup 48/Ca, and /sup 56/Fe has been measured at 60/sup 0/, 90/sup 0/, and 140/sup 0/ and at inelasticities up to and including the ..delta..(3,3) region. Longitudinal response functions in the momentum interval 300 MeV/c

Coulomb sum rule for /sup 40/Ca, /sup 48/Ca, and /sup 56/Fe for Q < or = 550 MeV/c

The elastic-electron scattering cross sections from $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$ have been measured at incident electron energies between 170 and 750 MeV. Cross sections were separated into their longitudinal (charge) and transverse (magnetic) contributions using the Rosenbluth formula. Values of the $^{3}\mathrm{He}$ charge form factor have been extracted to ${q}^{2}=20$ ${\mathrm{fm}}^{\ensuremath{-}2}$ and for the $^{3}\mathrm{He}$ magnetic form factor to ${q}^{2}=16$ ${\mathrm{fm}}^{\ensuremath{-}2}$. The $^{4}\mathrm{He}$ form factor has been determined up to 6.2 ${\mathrm{fm}}^{\ensuremath{-}2}$. Densities for the charge and magnetization have been deduced from phenomenological models used in a phase-shift solution of the Dirac equation. A model-independent determination of the nuclear densities has been performed in order to obtain realistic errors on the extracted distributions. After unfolding the nucleon size from the distributions the point density is shown to have a significant central depression for a radius 0.8 fm for both $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$. Comparison of the form factors is made with Faddeev and variational three-body calculations that use realistic two-body $\mathrm{NN}$ interactions. The influence of off-shell effects, three-body forces, meson-exchange corrections, and short-range correlations are discussed. At present no theoretical calculation that uses input derived entirely from nucleon-nucleon scattering is able to reproduce the experimental data.NUCLEAR REACTIONS $^{3,4}\mathrm{He}(e, {e}^{\ensuremath{'}})$, $E=170, 200, 250, 300, 350, 400, 450, 500, \mathrm{and} 750$ MeV; measured $\ensuremath{\sigma}(E, \ensuremath{\theta})$. Measured charge form factor $^{3}\mathrm{He}$ to ${q}^{2}=20$ ${\mathrm{fm}}^{\ensuremath{-}2}$ and magnetic form factor to ${q}^{2}=16$ ${\mathrm{fm}}^{\ensuremath{-}2}$. Measured $^{4}\mathrm{He}$ form factor to ${q}^{2}=6.2$ ${\mathrm{fm}}^{\ensuremath{-}2}$. Deduced nuclear charge, magnetic and point-nucleon distributions from model-independent analysis.

Electromagnetic structure of the helium isotopes

The electromagnetic structure of the ${\mathrm{He}}^{3}$ nucleus has been investigated by means of high-energy electron scattering. A separation of the charge and magnetic form factors has been accomplished. The charge form-factor data extend to ${q}^{2}=20$ ${\mathrm{fm}}^{\ensuremath{-}2}$ and exhibit a diffraction minimum at ${q}^{2}=11.6$ ${\mathrm{fm}}^{\ensuremath{-}2}$; the magnetic scattering is measured to ${q}^{2}=12.5$ ${\mathrm{fm}}^{\ensuremath{-}2}$. The results are discussed in terms of models for the charge and magnetic distributions of the nucleus.

Electromagnetic Structure of the He 3 Nucleus

Deep-inelastic inclusive electron-scattering cross sections from /sup 40/Ca, /sup 48/Ca, and /sup 56/Fe have been measured at 60/sup 0/, 90/sup 0/, and 140/sup 0/ and at energy transfers including the ..delta..(3,3) region. The transverse response function in the momentum interval 300 MeV/c

R. R. Whitney

Papers

Nuclear Fermi momenta from quasielastic electron scattering

Coulomb sum rule for /sup 40/Ca, /sup 48/Ca, and /sup 56/Fe for Q < or = 550 MeV/c

Electromagnetic structure of the helium isotopes

Electromagnetic Structure of the He 3 Nucleus

Transverse response functions in deep inelastic electron scattering for ca-40, ca-48, and fe-56