53 research outputs found
16O(e,e'p) reaction at large missing energy
We investigate the origin of the strength at large missing energies in
electron-induced proton knockout reactions. For that purpose the reaction
16O(e,e'p) was studied at a central value omega=210 MeV of the energy transfer,
and two values of the momentum transfer: q=300, 400 MeV/c, corresponding to the
"dip region". Differential cross sections were determined in a large range of
missing energy (Em=0-140 MeV) and proton emission angle (gamma_pq =0-110 deg),
and compared to predictions of a model that includes nucleon-nucleon
short-range correlations and two-body currents. It is observed that, in the
kinematic domain covered by this experiment, the largest contribution to the
cross section stems from two-body currents, while short-range correlations
contribute a significant fractionComment: submitted to Physics Letters
Investigation of the Exclusive 3He(e,e'pp)n Reaction
Cross sections for the 3He(e,e'pp)n reaction were measured over a wide range
of energy and three- momentum transfer. At a momentum transfer q=375 MeV/c,
data were taken at transferred energies omega ranging from 170 to 290 MeV. At
omega=220 MeV, measurements were performed at three q values (305, 375, and 445
MeV/c). The results are presented as a function of the neutron momentum in the
final-state, as a function of the energy and momentum transfer, and as a
function of the relative momentum of the two-proton system. The data at neutron
momenta below 100 MeV/c, obtained for two values of the momentum transfer at
omega=220 MeV, are well described by the results of continuum-Faddeev
calculations. These calculations indicate that the cross section in this domain
is dominated by direct two-proton emission induced by a one-body hadronic
current. Cross section distributions determined as a function of the relative
momentum of the two protons are fairly well reproduced by continuum-Faddeev
calculations based on various realistic nucleon-nucleon potential models. At
higher neutron momentum and at higher energy transfer, deviations between data
and calculations are observed that may be due to contributions of isobar
currents.Comment: 14 pages, 1 table, 17 figure
Signatures for short-range correlations in {16}O, observed in the reaction {16}O(e,e'pp){14}C.
The reaction O-16(e,e'pp)C-14 has been studied at a transferred four-momentum (omega,\q\) = (210 MeV, 300 MeV/c). The differential cross sections for the transitions to the ground state and the lowest excited states in C-14 were determined as a function of the momentum of the recoiling C-14 nucleus and the angle between the momentum of the proton emitted in the forward direction and the momentum transfer q. A comparison of the data to the results of calculations, performed with a microscopic model, shows clear signatures for short-range correlations in the O-16 ground state
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