IN ELECTRON (e,e' )-SCATTERING FROM 12C
E.L. Kuplennikova), Yu.N. Ranyuka),
V.V.Krasil'nikovb),
I.A. Levashovb)
a)National Science Center "Kharkov Institute of Physics and Technology", Kharkov, Ukraine
b)Belgorod State University, Belgorod, Russia,
In inclusive inelastic electron scattering there is a broad "quasi-free peak" which corresponds to the elastic scattering of an electron by a moving nucleon bound in a nucleus. The quasifree peak centroid is located at approximately the same electron energy loss as that for electrons scattered from a nucleon at rest. The small shift, which take place between two peaks (e ), has been interpreted as an average nucleon separation energy that must be supplied to knock the nucleon out of the nucleus.
At present a great body of experimental data on the q- dependences of the quasifree peak position on light nuclei have already been accumulated. Measurements cover the wide range of 3- momentum transfers q~ 0,8-5 fm-1. It turned out that the experimental e (q)-dependences demonstrate strong dependence from kinematical conditions and for the exception of the 2H nucleus had a minimum. Systematic measurements of the inclusive quasifree cross sections from different nuclei have spurred considerable theoretical effort to understand them. The need for such attention is partly a consequence of the failure of traditional models to explain the value of the shift for different nuclei and its behavior from kinematical conditions.
In order to better understand the phenomena involved in the scattering processes we have made a review of the modern state of the experimental and theoretical investigations of the q- dependence of the quasifree peak maximum for the 12C(e,e' )- reaction relatively to the free eN- cross section peak. The influence of the different processes on the quasifree peak location is considered. Except for nuclear binding these effects are expected to be small, but they all provide information about the nuclear environment.
It was shown that the simple theoretical calculations are not able to reproduce the experimental e (q)- dependence, indicating that other reaction mechanisms play a non-negligible role. At the same time more complicated models using the approach in which the shifts are due to the exchange and nonlocal character of NN- interaction give a satisfactory description of the experimental data. Besides, calculations in the relativistic s-w model are shown that the characteristic minimum in the e (q)- dependence may be a result of antisymmetrization of final nuclear states.