[en] The Hall A RICH at Jefferson Lab is undergoing an upgrade to adapt to the higher momentum kinematics of the neutron spin structure Transversity experiments planned to run in 2008. The JLab RICH is a proximity focusing detector using liquid C6F14 as Cherenkov radiator, a thin layer of CsI as photon converter, evaporated on segmented pad panels of a proportional chamber. The original RICH had a superior hadron identification up to 2 GeV/c with pion/kaon rejection at the level of 1:1000 at ∼90% intrinsic efficiency. The upgrade will extend this performance above 2.4 GeV/c by means of a larger photon detector (a multiwire-multipad proportional chamber) and a longer proximity gap which will improve the photon detection geometrical efficiency and the angular resolution, respectively.

[en] A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data

[en] An experimental study of the 16O(e, e'K+)16N_#Lambda# reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e, e'K+)Λ,Σ₀ exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76 ± 0.16 MeV was obtained for 16N_#Lambda# with better precision than previous measurements on the mirror hypernucleus 16O_#Lambda#. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p1/2 and p3/2 hole states of the 15N core nucleus.