Precise Measurement of Deuteron Tensor Analyzing Powers with BLAST

We report a precision measurement of the deuteron tensor analyzing powers T20 and T21 at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range Q=2.15-4.50 fm-1 with the Bates Large Acceptance Spectrometer Toroid using a highly polarized deuterium internal gas target. The data are in excellent agreement with calculations in a framework of effective field theory. The deuteron charge monopole and quadrupole form factors GC and GQ were separated with improved precision, and the location of the first node of GC was confirmed at Q=4.19±0.05 fm-1. The new data provide a strong constraint on theoretical models in a momentum transfer range covering the minimum of T20 and the first node of GC.