The A(Q$^2$) deuteron structure function from the Jefferson Lab t$_20$ experiment

Differential cross-sections for electron deuteron elastic scattering were measured in a 4-momentum transfer range between 0.66 and 1.80 (GeV/c)2. This experiment was performed in the Hall C of the Jefferson Laboratory in 1997. The 80 muA electron beam was incident upon a 4.5 cm liquid deuterium target. The scattered electrons were measured in the high momentum spectrometer HMS, in coincidence with recoil deuterons. A specifically designed magnetic spectrometer and the upstream part of the POLDER polarimeter were used to detect the deuterons. A special collimator in HMS ensured a precise knowledge of the solid angle and a complete match between the two spectrometers. From these data, the A(Q) structure function was extracted with typical uncertainties of +- 5 percent. These new data resolve discrepancies between older experiments (in particular between Saclay and SLAC) [ARN75,BOS90,PLA90] and allow a precise comparison with theoretical models of the deuteron electromagnetic structure.