Cross sections for the He(e, e'p)R reaction have been measured for recoil momenta between 225 and 500 MeV/c. We find (1) that in the continuum channel a peak in the missing energy spectrum appears which shifts with increasing recoil momentum in a predictable way, and (2) that for the highest recoil momenta (above 300 or 350 MeV/c) overall agreement is obtained with microscopic calculations in which the scattering on nucleon pairs predominates. These results strongly suggest that the highest recoil momenta are generated by the scattering on one of a pair of nucleons. This interpretation is reinforced by an observed continuum momentum distribution which, for high recoil momenta, resembles the momentum distribution of deuterium. We infer that the high momentum part of the momentum distribution of a nucleon pair appears unmodi6ed when embedded in a nuclear medium.PACS number(s): 21.45.+v, 21.30. +y, 25.30. Fj
Coincident neutron-proton pairs were measured from the reaction 'He(y, np)p with a 100-MeV bremsstrahlung beam. The energy and angle of the neutron and proton were used to reconstruct the photon energy, making this a kinematically complete experiment. Quasi-deuteron breakup was observed for photon energies from 45 to 95 MeV. The angular distribution of the np pairs was measured for opening angles from 122 to 202 degrees in the laboratory frame. The single-differential cross section in Qp was determined at Op = 81, relative to deuterium, to range from 2.4 at 55 MeV to 1.7 at 95 MeV.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.