Measurement of Tensor Analyzing Powers in Elastic Electron Deuteron Scattering with BLAST

A precision measurement of the deuteron tensor analyzing powers $T_{20}$ and $T_{21}$ in elastic electron-deuteron scattering has been carried out at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range of 2.15 to 4.5 fm$^{-1}$ using a polarised, stored electron beam; the Bates Large Acceptance Spectrometer Toroid (BLAST) detector; and a highly polarized, internal deuterium gas target. The elastic deuteron form factors $G_C$ and $G_Q$ were extracted with improved precision using the new data; confirming the location of the first node of the charge monopole form factor. The new data provide strong constraints on nuclear models in a momentum transfer range covering the minimum of $T_{20}$ and the first node of $G_C$.