Jlab experiment E04-018 was approved in 2004 to do measurements of
elastic electron scattering off the 3He and 4He
few-body systems up to the highest momentum transfers possible, limited by
cross section sensitivity. The measurements will extend our knowledge of
the elastic form factors of the helium isotopes down by more than one order
in magnitude and out in Q2 possibly by more than a factor of
two. The experiment will use the Hall A Facility of Jlab. Scattered
electrons will be detected in the Electron High Resolution Spectrometer.
Electron-recoil nucleus coincidences will be identified by double- arm
time-of-flight. The effective double-arm solid angle and radiative
corrections for the evaluation of the cross sections will be determined
by means of a Monte Carlo simulation. The results are expected to play
a crucial role in establishing a consistent standard model describing
the structure of few-body nuclei in terms of nucleons and mesons, and
in possibly providing evidence for its break-down at "large" momentum
transfers, where the quark-gluon degrees of freedom are expected
to dominate.
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