Existing cross-section data for 1p-shell knockout in the reaction 12C(e,e′ p)11B - as obtained under different kinematic conditions - are shown to be mutually consistent, apart from a recent measurement performed in Mainz. New data have been collected at the Amsterdam Pulse Stretcher that confirm the normalization of the older measurements. An analysis of the world's 12C(e,e′ p)11B data has yielded precise values of the spectroscopic factor for 1p-shell and 1s-shell knockout from 12C. These values have been used to evaluate the transparency of the 12C nucleus for 1p-shell and 1s-shell protons separately on the basis of recent high-energy 12C(e,e′ p)11B data taken at a four-momentum transfer squared Q2 of 1.1 (GeV/c)2. As the resulting average value of the nuclear transparency, 0.81±0.04, is considerably higher than the value obtained from previous analyses and theoretical estimates, the high Q2 data were used instead for an independent determination of the spectroscopic strength for 1p+1s knockout. Combining these results with the low Q2 data the spectroscopic factors appear to be momentum-transfer dependent. Possible explanations of these surprising results in terms of reaction-mechanism effects or a possible breakdown of the quasiparticle concept at high Q2 are discussed as well.
|Original language||English (US)|
|Number of pages||5789261|
|Journal||Physical Review C - Nuclear Physics|
|State||Published - Jan 1 2000|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics