Related papers: On the treatment of the $\Delta$-contribution in e…
The contribution of the $\Delta$(1232) isobar to the electromagnetic current of the two-nucleon system and its role in ($\gamma$,NN) processes is investigated. The difference between the genuine $\Delta$-excitation current and that part of…
Results for the cross sections of the exclusive 16O(e,e'pn)14N and 16O(gamma,pn)14N knockout reactions are presented and discussed in different kinematics. In comparison with earlier work, a complete treatment of the center-of-mass (CM)…
The attempts to investigate correlations in electromagnetically induced one- and two-nucleon knockout are reviewed. The theoretical framework for cross section calculations is outlined and some results are presented for the exclusive…
The cross sections of the ($e,e'N$) and ($\gamma,p$) reactions on $^{16}$O are calculated, for the transitions to the $1/2^{-}$ ground state and the first $3/2^{-}$ excited state of the residual nucleus, using single-particle overlap…
Recent advances in the description of electromagnetic two-nucleon knockout reactions are reviewed. The sensitivity to different types of correlations and to their treatment in the nuclear wave functions, the effects of final-state…
The role of center-of mass (CM) effects in the one-body nuclear current in the description of electromagnetically induced two-nucleon knockout reactions is discussed in connection with the problem of the lack of orthogonality between…
The contributions of short-range nucleon-nucleon correlations, meson exchange current (MEC) corrections and the influence of Delta isobar excitations (isobaric currents, IC) on photon induced two-nucleon knockout reactions are investigated.…
The contributions from $^{12}$C$(e,e'pn)$ and $^{12}$C$(e,e'pp)$ to the semi-exclusive $^{12}$C$(e,e'p)$ cross section have been calculated in an unfactorized model for two-nucleon emission. We assume direct two-nucleon knockout after…
The contributions of short-range nucleon-nucleon (NN) correlations, various meson exchange current (MEC) terms and the influence of $\Delta$ isobar excitations (isobaric currents, IC) on exclusive two-nucleon knockout reactions induced by…
Resolution of discrete final states in the $^{16}$O(e,e$'$pp)$^{14}$C reaction may provide an interesting tool to discriminate between contributions from one- and two-body currents in this reaction. This is based on the observation that the…
The cross sections for electron induced two-nucleon knockout reactions are evaluated for the example of the $^{16}$O(e,e$'$pn)$^{14}$N reaction leading to discrete states in the residual nucleus $^{14}$N. These calculations account for the…
We generalize the spectral-function formalism to describe two-nucleon knockout processes in exclusive kinematics. Significant improvements are introduced both in the treatment of the current operators entering the $\Delta$-current…
After a brief overview of relevant studies on one-nucleon knockout showing the importance of quantitatively understanding the origin of the quenched spectroscopic factors extracted from data, attention is focussed on two-nucleon emission as…
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…
Cross sections and photon asymmetries of the exclusive 16O(\gamma,pn)14N and 16O(\gamma,pp)14C knockout reactions are calculated for transitions to the low-lying discrete final states of the residual nucleus in the photon-energy range…
The $\pi$, $\eta$ and $\rho$ exchange contributions to the cross-section for the reaction $pp\to pp\eta$ near threshold are calculated with a phenomenological description of the intermediate S11 (N(1535)) resonance for all exchange…
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…
The similarities in the experimental indications for multinucleon mechanisms in $(\gamma,p)$ and $(e,e'p)$ processes are pointed out. For both types of reactions, the substantial role of two-nucleon emission processes for transitions to…
After recent improvements to the Pavia model of two-nucleon knockout from $^{16}$O with electromagnetic probes the calculated cross sections are compared to experimental data from such reactions. Comparison with data from a measurement of…
Relativistic calculations for the quasifree electron scattering process (e, e'p) and the direct knockout contribution to (gamma, p) reactions are presented. The spectroscopic factors determined from the former reaction are used to fix the…