Quasielastic Scattering of Polarized Electrons from PolarizedHe3and Measurement of the Neutron's Form Factors

We report measurements of asymmetries in quasielastic scattering of polarized electrons from polarized {sup 3}He at {ital Q}{sup 2}={minus}0.2 (GeV/{ital c}){sup 2}. We measure {ital A}{sub {ital T}{prime}}=({minus}2.6{plus minus}0.9{plus minus}0.46)% and {ital A}{sub {ital T}{ital L}{prime}}=(+1.75{plus minus}1.2 {plus minus}0.31)%. The asymmetry {ital A}{sub {ital T}{prime}} depends predominantly on the previously measured neutron magnetic form factor and provides a test of theories of spin-dependent quasielastic scattering. Our result for {ital A}{sub {ital T}{prime}} is consistent with a previously reported measurement and suggests that the current theoretical picture is incomplete and final-state-interaction and meson-exchange corrections are necessary if the electric form factor of the neutron is to be reliably extracted from the asymmetry {ital A}{sub {ital T}{ital L}{prime}}.