J.F. Danel

Longitudinal and transverse responses in quasi-elastic electron scattering from 208Pb and 4He

Abstract Longitudinal and transverse response functions, R L and R T , have been obtained in inclusive quasi-elastic electron scattering from 4 He and 208 Pb, for momentum transfers between 300 and 650 MeV/ c and energy transfers up to 350 MeV. A quenching of R L , ∼ 14% in 4 He and ∼ 50% in 208 Pb has been observed. Interpretations in terms of correlations and modification of nucleon form factors in the nuclear medium are discussed.

A waterfall target for electron scattering experiments

A windowless waterfall target for electron scattering experiments on 16O is described. The thickness of the laminar film, adjustable between ∼ 45 mg/cm2 and ∼ 140 mg/cm2, has been proven to be particularly stable in time (within ± 0.5%) and insensitive to beam current up at least 20 μA. The whole target system remotely monitored on-line.

Anomaly in the Transverse Response of 3He(e,e’p) Reaction for High Recoil Momentum

The nucleon-nucleon interaction at short distance inside the nucleus can be studied through (e,e’p) experiments at high recoil momenta in the continuum. In order to clarify the reaction mechanism in such experiments, a separation of the Transverse (T) and longitudinal (L) components of the 3He(e,e’p) cross section was performed at the highest possible recoil momentum, 260 Mev/c. The longitudinal response is found nearly compatible with microscopic calculations. These calculations predict an enhancement of the transverse response due to reaction mechanism (a factor 1.6) but they are still about a factor 3 lower than the data.