New results from the bates large acceptance spectrometer toroid (blast)

An experiment using the novel technique of scattering a longitudinally polarized electron beam from polarized internal hydrogen/deuterium gas targets was carried out in the South Hall Ring at the MIT-Bates Accelerator Center. The scattered particles were detected by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The proton electric to magnetic form factor ratio, $\frac{G-E^p}{G-M^p}$ at Q² = 0.1 - 0.65 (GeV/c) ² has been determined from the experiment by measuring the spin-dependent ep elastic scattering asymmetry in the two symmetric sectors of the BLAST simultaneously for the first time. The neutron electric form factor $G-E^n$ in the same Q² range has been extracted by measuring the spin-dependent asymmetry from the $\vec d(\vec e,e'n)$ process with a vector polarized deuterium target. These results on the nucleon form factors from the BLAST experiment are presented. © 2009 World Scientific Publishing Company.

Duke Scholars

Author Haiyan Gao Physics