Stephen Wood

Light Nuclei of Even Mass Number in the Skyrme Model

We consider the semiclassical rigid-body quantization of Skyrmion solutions of mass numbers B = 4, 6, 8, 10, and 12. We determine the allowed quantum states for each Skyrmion and find that they often match the observed states of nuclei. The spin and isospin inertia tensors of these Skyrmions are accurately calculated for the first time and are used to determine the excitation energies of the quantum states. We calculate the energy level splittings, using a suitably chosen parameter set for each mass number. We find good qualitative and encouraging quantitative agreement with experiment. In particular, the rotational bands of beryllium-8 and carbon-12, along with isospin 1 triplets and isospin 2 quintets, are especially well reproduced. We also predict the existence of states that have not yet been observed and make predictions for the unknown quantum numbers of some observed states.

Proton G_E/G_M from beam-target asymmetry

The ratio of the protons electric to magnetic form factor, G{sub E}/G{sub M}, can be extracted in elastic electron-proton scattering by measuring cross sections, beam-target asymmetry, or recoil polarization. Separate determinations of G{sub E}/G{sub M} by cross sections and recoil polarization observables disagree for Q{sup 2}>1 (GeV/c){sup 2}. Measurement by a third technique might uncover an unknown systematic error in either of the previous measurements. The beam-target asymmetry has been measured for elastic electron-proton scattering at Q{sup 2} = 1.51 (GeV/c){sup 2} for target spin orientation aligned perpendicular to the beam momentum direction. This is the largest Q{sup 2} at which G{sub E}/G{sub M} has been determined by a beam-target asymmetry experiment. The result, {mu}G{sub E}/G{sub M}=0.884{+-}0.027{+-}0.029, is compared to previous world data.

Light nuclei as quantized skyrmions

We consider the rigid-body quantization of Skyrmions with topological charges 1 to 8, as approximated by the rational map ansatz. Novel general expressions for the elements of the inertia tensors, in terms of the approximating rational map, are presented and are used to determine the kinetic energy contribution to the total energy of the ground and excited states of the quantized Skyrmions. Our results are compared to the experimentally determined energy levels of the corresponding nuclei, and the energies and spins of a few as yet unobserved states are predicted.

Reparametrizing the Skyrme model using the lithium-6 nucleus

The minimal-energy

Hypernuclear spectroscopy using the (e, e'K+) reaction

B=6

Measurements of Electron Proton Elastic Cross Sections for 0.4

solution of the Skyrme model is a static soliton with

Measurement of R = {sigma}{sub L}/{sigma}{sub T} and the Separated Longitudinal and Transverse Structure Functions in the Nucleon Resonance Region

{D}_{4d}

Light Nuclei as Quantized Skyrmions: Energy Spectra and Form Factors

symmetry. The symmetries of the solution imply that the quantum numbers of the ground state are the same as those of the lithium-6 nucleus. This identification is considered further by obtaining expressions for the mean charge radius and quadrupole moment, dependent only on the Skyrme model parameters

NEUTRON ELECTRIC FORM FACTOR VIA RECOIL POLARIMETRY

e

Spin Structure Moments of the Proton and Deuteron

(a dimensionless constant) and