Eur. Phys. J. A (2004) 20: 233-244
https://doi.org/10.1140/epja/i2003-10139-6

NN final-state interaction in two-nucleon knockout from ¹⁶ O

¹ Dipartimento di Fisica Nucleare e Teorica dell’Universitá degli Studi di Pavia, I-27100, Pavia, Italy
² Institut für Kernphysik, Johannes Gutenberg-Universität, D-55099, Mainz, Germany
³ Dipartimento di Fisica Nucleare e Teorica dell’Universitá degli Studi di Pavia, I-27100, Pavia, Italy
⁴ Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, I-27100, Pavia, Italy

^* e-mail: schwamb@kph.uni-mainz.de

Abstract

The influence of the mutual interaction between the two outgoing nucleons (NN-FSI) in electro- and photoinduced two-nucleon knockout from ¹⁶ O has been investigated perturbatively. It turns out that the effect of NN-FSI depends on the kinematics and on the type of reaction considered. The effect is generally larger in pp- than in pn-knockout and in electroinduced than in photoinduced reactions. In superparallel kinematics NN-FSI leads in the (e,e‘pp) channel to a strong increase of the cross-section, that is mainly due to a strong enhancement of the -current contribution. In pn-emission, however, this effect is partially cancelled by a destructive interference with the seagull current. For photoreactions NN-FSI is considerably reduced in superparallel kinematics and can be practically negligible in specific kinematics.