Precise Measurement of Deuteron Tensor Analyzing Powers with BLAST

We report a precision measurement of the deuteron tensor analyzing powers T{sub 20} and T{sub 21} at the MIT- BatesLinear Accelerator Center. Data were collected simultaneously over a momentum transferrange Q=2.15-4.50 fm{sup -1} with the BatesLarge 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 G{sub C} and G{sub Q} were separated with improved precision, and the location of the first node of G{sub C} was confirmed at Q=4.19{+-}0.05 fm{sup -1}. The new data provide a strong constraint on theoretical models in a momentum transferrange covering the minimum of T{sub 20} and the first node of G{sub C}.