Numerical computation of real or complex elliptic integrals

Algorithms for numerical computation of symmetric elliptic integrals of all three kinds are improved in several ways and extended to complex values of the variables (with some restrictions in the case of the integral of the third kind). Numerical check values, consistency checks, and relations to Legendre's integrals and Bulirsch's integrals are included

Leading-Log Effects in the Resonance Electroweak Form Factors

We study log corrections to inelastic scattering at high Bjorken x for Q^2 from 1 to 21 GeV^2. At issue is the presence of log corrections, which can be absent if high x scattering has damped gluon radiation. We find logarithmic correction of the scaling curve extrapolated to low Q^2 improves the duality between it and the resonance plus background data in the Delta region, indicating log corrections exist in the data. However, at W > 2 GeV and high x, the data shows a (1-x)^3 form. Log corrections in one situation but not in another can be reconciled by a W- or Q^2- dependent higher twist correction.Comment: 13 pages, report nos. RPI-94-N90 and WM-94-106, revtex, two figures (available by fax or post

A pure S-wave covariant model for the nucleon

Using the manifestly covariant spectator theory, and modeling the nucleon as a system of three constituent quarks with their own electromagnetic structure, we show that all four nucleon electromagnetic form factors can be very well described by a manifestly covariant nucleon wave function with zero orbital angular momentum. Since the concept of wave function depends on the formalism, the conclusions of light-cone theory requiring nonzero angular momentum components are not inconsistent with our results. We also show that our model gives a qualitatively correct description of deep inelastic scattering, unifying the phenomenology at high and low momentum transfer. Finally we review two different definitions of nuclear shape and show that the nucleon is spherical in this model, regardless of how shape is defined.Comment: 20 pages and 10 figures; greatly expanded version with new fits and discussion of DIS; similar to published versio

Scaling and Duality in Semi-exclusive Processes

We discuss extending scaling and duality studies to semi-exclusive processes. We show that semi-exclusive hard pion photoproduction should exhibit scaling behavior in kinematic regions where the photon and pion both interact directly with the same quark. We show that such kinematic regions exist. We also show that the constancy with changing momentum transfer of the resonance peak/scaling curve ratio, familiar for many resonances in deep inelastic scattering, is also expected in the semi-exclusive case.Comment: 8 pages, 4 figures, submitted to Phys.Rev.

Quantum Monte Carlo calculations of neutron-alpha scattering

We describe a new method to treat low-energy scattering problems in few-nucleon systems, and we apply it to the five-body case of neutron-alpha scattering. The method allows precise calculations of low-lying resonances and their widths. We find that a good three-nucleon interaction is crucial to obtain an accurate description of neutron-alpha scattering.Comment: 4 pages, 2 figures, submitted to Physical Review Letter

Quantum Monte Carlo Calculations of A≤6A\leq6 Nuclei

The energies of $^{3}H$, $^{3}He$, and $^{4}He$ ground states, the ${\frac{3}{2}}^{-}$ and ${\frac{1}{2}}^{-}$ scattering states of $^{5}He$, the ground states of $^{6}He$, $^{6}Li$, and $^{6}Be$ and the $3^{+}$ and $0^{+}$ excited states of $^{6}Li$ have been accurately calculated with the Green's function Monte Carlo method using realistic models of two- and three-nucleon interactions. The splitting of the $A=3$ isospin $T=\frac{1}{2}$ and $A=6$ isospin $T=1$, $J^{\pi} = 0^{+}$ multiplets is also studied. The observed energies and radii are generally well reproduced, however, some definite differences between theory and experiment can be identified.Comment: 12 pages, 1 figur

Monolithic Arrays of Grating-Surface-Emitting Diode Lasers and Quantum Well Modulators for Optical Communications

The electro-optic switching properties of injection-coupled coherent 2-D grating-surface-emitting laser arrays with multiple gain sections and quantum well active layers are discussed and demonstrated. Within such an array of injection-coupled grating-surface-emitting lasers, a single gain section can be operated as intra-cavity saturable loss element that can modulate the output of the entire array. Experimental results demonstrate efficient sub-nanosecond switching of high power grading-surface-emitting laser arrays by using only one gain section as an intra-cavity loss modulator

Approach to Perturbative Results in the N-Delta Transition

We show that constraints from perturbative QCD calculations play a role in the nucleon to Delta(1232) electromagnetic transition even at moderate momentum transfer scales. The pQCD constraints, tied to real photoproduction data and unseparated resonance response functions, lead to explicit forms for the helicity amplitudes wherein the E2/M1 ratio remains small at moderately large momentum transfer.Comment: 4 pages, 2 figures, ReVTe

Experimental and Theoretical Results for Weak Charge Current Backward Proton Production

In this paper, we do three things in the study of deuteron break-up by high energy neutrino beams. (1) We present previously unpublished data on neutrino induced backward protons from deuteron targets; (2) we calculate the contributions from both the two-nucleon (2N) and six-quark (6q) deuteron components, which depend upon the overall normalization of the part that is 6q; and (3) we suggest other signatures for distinguishing the 2N and 6q clusters. We conclude that the 6q cluster easily explains the shape of the high momentum backward proton spectrum, and its size is nicely explained if the amount of 6q is one or a few percent by normalization of the deuteron. There is a crossover, above which the 6q contribution is important or dominant, at 300--400 MeV/c backward proton momentum.Comment: 8 pages, 5 figure

Suspected Canine Zinc Toxicosis Caused by Ingestion of Pennies

A 21 pound, nine year old spayed female Shih Tzu was presented to the Oradell Animal Hospital at 3 a.m. on Sunday morning with a complaint of anorexia, lethargy and vomiting for the past two days. The dog\u27s previous medical history was unremarkable, except for being hit by a car in November 1983. A right ilial fracture sustained at that time had been plated. The animal was current on all routine vaccinations