Quarks and Leptons: An Introductory Course in Modern Particle Physics

A Measurement of the neutron electric form factor at very large momentum transfer using polaried electrions scattering from a polarized helium-3 target

“…Following the excellent description in Quarks & Leptons by F. Halzen and A.D. Martin [16], the simplest physical case study of the electromagnetic interactions of relativistic particles is the scattering of elementary, charged, spin-1 2 particles. The proper description for this sort of interaction is the Dirac equation.…”

Measurement of the neutron (³He) spin structure functions at low Q²: A connection between the Bjorken and gerasimov-drell-hearn sum rule

“…Furthermore, the targets can be made in relatively pure form, avoiding the severe dilution effects of ND 3 ammonia cells. However, the nuclear corrections are more pronounced in 3 He and require sophisticated corrections to the data.…”

“…1.1. As compared to the other choice of using polarized deuterium as a source for polarized neutrons, 3 He targets are easier to make and require a weak holding field compared to current deuterated ammonia targets, which must be brute force polarized by using superconducting magfnets at high fields which can have the effect of distorting incident and outgoing electron momenta. Furthermore, the targets can be made in relatively pure form, avoiding the severe dilution effects of ND 3 ammonia cells.…”

“…In 3 He, the two protons couple to zero spin as a first approximation. Therefore, polarized 3 He is a good approximation to a free neutron target; see Fig. 1.1.…”

“…Jefferson Laboratory experiment E94-010 [1], also known as the GDH experiment, with co-spokepersons Z.-E. Meziani, G. Cates, and J.-P. Chen (for a complete list of collaborators and institutions represented, see the addendum) was an experiment with many firsts: It was the commissioning experiment for the newly formed polarized 3 He collaboration at the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory), in Newport News, Virginia. It was the first experiment to run at this laboratory requiring both polarized beam and a polarized target from September 25 to December 24, 1998.…”