Separated response function ratios in exclusive, forward π(±) electroproduction.

The study of exclusive π(±) electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=σL(π-)/σL(π+) is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=σT(π-)/σT(π+) from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks.

Transverse beam spin asymmetries in forward-angle elastic electron-proton scattering.

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2=0.15, 0.25 (GeV/c)2.

Strange-quark contributions to parity-violating asymmetries in the forward g0 electron-proton scattering experiment.

We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < or =Q2 < or =1.0 GeV2.

Recoil polarization for delta excitation in pion electroproduction.

We measured angular distributions of recoil-polarization response functions for neutral pion electroproduction for W = 1.23 GeV at Q(2) = 1.0 (GeV/c)(2), obtaining 14 separated response functions plus 2 Rosenbluth combinations; of these, 12 have been observed for the first time.

Angular distributions for (3,4)(Lambda)H bound states in the (3,4)He(e,e(')K+) reaction.

The (3,4)(Lambda)H and (4)(Lambda)H hypernuclear bound states have been observed for the first time in kaon electroproduction on (3,4)He targets. The production cross sections have been determined at Q(2)=0.35 GeV2 and W=1.

Measurement of the electric form factor of the neutron at Q2=0.5 and 1.0 GeV2/c2.

The electric form factor of the neutron was determined from measurements of the d-->(e-->,e'n)p reaction for quasielastic kinematics. Polarized electrons were scattered off a polarized deuterated ammonia (15ND3) target in which the deuteron polarization was perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle detector.

Longitudinal electroproduction of charged pions from (1)H, (2)H, and (3)He.

Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.

Measurement of the high energy two-body deuteron photodisintegration differential cross section.

The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at straight theta(cm) = 37 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E(gamma) greater, similar 1.

Measurement of the electric form factor of the neutron through d-->(e-->,e(')n)p at Q2 = 0.5 (GeV/c)(2).

We report the first measurement using a solid polarized target of the neutron electric form factor G(n)(E) via d-->(e-->,e(')n)p. G(n)(E) was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia ( 15ND3). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer.

Measurement of the charged pion electromagnetic form factor.

Separated longitudinal and transverse structure functions for the reaction 1H(e,e(')pi(+))n were measured in the momentum transfer region Q2 = 0.6--1.6 (GeV/c)(2) at a value of the invariant mass W = 1.

Measurement of tensor polarization in elastic electron-deuteron scattering at large momentum transfer.

Tensor polarization observables ( t(20), t(21), and t(22)) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c)(2).