B. Hu

Proton Spin Structure in the Resonance Region

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeV<W<1.910 GeV) at an average four momentum transfer of Q2=1.3 GeV2. Using the Jefferson Lab polarized electron beam, a spectrometer, and a polarized solid target, we measured the asymmetries A|| and A(perpendicular) to high precision, and extracted the asymmetries A1 and A2, and the spin structure functions g1 and g2. We found a notably nonzero A(perpendicular), significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality.

Fast neutron scattering on Gallium target at 14.8 MeV

Abstract Benchmarking of evaluated nuclear data libraries was performed for ∼14.8 MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy (CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by ∼14.8 MeV neutrons and leakage neutron energy spectra were measured at 60° and 120°. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around E n = 10 – 13 MeV . All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

Probing Quark-Gluon Interactions with Transverse Polarized Scattering

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.

High resolution spectroscopic study of Be Λ10

Spectroscopy of a

Isotope Effect in Tunneling Ionization of Neutral Hydrogen Molecules

^{10}_{\Lambda}

Measurement of the neutron electric form factor via recoil polarimetry

Be hypernucleus was carried out at JLab Hall C using the

High resolution spectroscopic study of

(e,e^{\prime}K^{+})

^{10}_{\Lambda}

reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of 0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using the

Be

p(e,e^{\prime}K^{+})\Lambda,\Sigma^{0}

Kaon, pion, and proton associated photofission of Bi nuclei

reactions allowed us to determine the energy levels, and the binding energy of the ground state peak (mixture of 1