Christopher Douglas Keith

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.

Test of parity-conserving time-reversal invariance using polarized neutrons and nuclear spin aligned holmium.

A test of parity-conserving, time-reversal noninvariance (PC TRNI) has been performed in 5.9 MeV polarized neutron transmission through nuclear spin aligned holmium. The experiment searches for the T-violating fivefold correlation via a double modulation technique{emdash}flipping the neutron spin while rotating the alignment axis of the holmium. Relative cross sections for spin-up and spin-down neutrons are found to be equal to within 1.2{times}10{sup {minus}5} (80{percent} confidence). This is a two orders of magnitude improvement compared to traditional detailed balance studies of time reversal, and represents the most precise test of PC TRNI in a dynamical process, to our knowledge. {copyright} {ital 1997} {ital The American Physical Society}

Measurements of the total cross section for the scattering of polarized neutrons from polarized {sup 3}He

Measurements of polarized-neutron--polarized

3He melting curve thermometry in a nuclear polarization experiment

{\mathrm{\ensuremath{-}}}^{3}

The scattering of polarized neutrons from statically polarized solid 3He

He scattering are reported. The target consisted of cryogenically polarized solid

Measurements at Low Energies of the Polarization-Transfer Coefficient

^{3}\mathrm{He}

An experimental test of parity‐even time reversal invariance with MeV neutrons

, with thickness 0.04 atom/b and polarization \ensuremath{\sim}0.4. Polarized neutrons were produced via the

A polarized solid 3He target for neutron transmission experiments

^{3}\mathrm{H}

Testing P‐even time reversal invariance with MeV neutrons

(p\ensuremath{\rightarrow},n\ensuremath{\rightarrow}

Measurement of the polarized neutron—polarized 3He total cross section

{)}^{3}