Empirical Fit to Inelastic Electron-Deuteron and Electron-Neutron Resonance Region Transverse Cross Sections

An empirical fit is described to measurements of inclusive inelastic electron-deuteron cross sections in the kinematic r ange of four-momentum transfer $0 \le Q^2<10$ GeV$^2$ and final state invariant mass $1.1<W<3.2$ GeV. The deuteron fit relies on a fit of the ratio $R_p$ of longitudinal to transverse cross sections for the proton, and the assumption $R_p=R_n$. The underlying fit parameters describe the average cross section for proton and neutron, with a plane-wave impulse approximation used to fit to the deuteron data. An additional term is used to fill in the dip between the quasi-elastic peak and the $\Delta(1232)$ resonance. The mean deviation of data from the fit is 3%, with less than 4% of the data points deviating from the fit by more than 10%.Comment: 16 pages, 5 figures, submitted to Phys. Rev. C. Text clarified in response to referee comment

One Year Out: Experiences of Prisoners Returning to Cleveland

Presents findings from a longitudinal study of prisoner reentry, documenting the lives of nearly three hundred former prisoners and their ability to find stable housing, reunite with family, secure employment, and avoid substance use and recidivism

Effective Spectral Function for Quasielastic Scattering on Nuclei

Spectral functions that are used in neutrino event generators to model quasielastic (QE) scattering from nuclear targets include Fermi gas, Local Thomas Fermi gas (LTF), Bodek-Ritchie Fermi gas with high momentum tail, and the Benhar-Fantoni two dimensional spectral function. We find that the $\nu$ dependence of predictions of these spectral functions for the QE differential cross sections (${d^2\sigma}/{dQ^2 d\nu}$) are in disagreement with the prediction of the $\psi'$ superscaling function which is extracted from fits to quasielastic electron scattering data on nuclear targets. It is known that spectral functions do not fully describe quasielastic scattering because they only model the initial state. Final state interactions distort the shape of the differential cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the $\psi'$ superscaling formalism can be well described with a modified {\it {effective spectral function}} (ESF). By construction, models using ESF in combination with the transverse enhancement contribution correctly predict electron QE scattering data.Comment: 16 pages, 23 figures, submitted to Eur. Phy. J.

The Effects of Class Size on Student Achievement in Higher Education: Applying an Earnings Function

This paper uses an earnings function to model how class size affects the grade students earn. We test the model using an ordinal logit with and without fixed effects on 363,023 undergraduate observations. We find that class size negatively affects grades. Average grade point declines as class size increases, precipitously up to class sizes of ten, and more gradually but monotonically through class sizes of 400 plus. The probability of getting a B plus or better declines from 0.9 for class sizes 20 to about 0.5 for class sizes of 120 and almost 0.4 for class sizes of 400

Resolving the Axial Mass Anomaly in neutrino Scattering

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

Quark-hadron duality in neutrino scattering

We present a phenomenological model of the quark-hadron transition in neutrino-nucleon scattering. Using recently extracted weak nucleon transition form factors, we investigate the extent to which local and global quark-hadron duality is applicable in the neutrino F_1, F_2 and F_3 structure functions, and contrast this with duality in electron scattering. Our findings suggest that duality works relatively well for neutrino-nucleon scattering for the F_2 and F_3 structure functions, but not as well for F_1. We also calculate the quasielastic, resonance and deep inelastic contributions to the Adler sum rule, and find it to be satisfied to within 10% for 0.5 < Q^2 < 2 GeV^2.Comment: 28 pages, 6 figure