Related papers: Treatment of the $\Delta$ current in electromagnet…
The treatment of the $\Delta$-current and its contribution in the exclusive $^{16}$O$(e,e'pp)^{14}$C and $^{16}$O$(\gamma,pp)^{14}$C knockout reactions are investigated in combination with the effects of correlations. Different…
$\Delta$ isobar components in the nuclear many-body wave function are investigated for the deuteron, light nuclei (${}^{16}O$) and infinite nuclear matter within the framework of the coupled-cluster theory. The predictions derived for…
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…
A new non-relativistic expansion in terms of the nucleon's momentum inside nuclear matter of the current for isobar electro-excitation from the nucleon is performed. Being exact with respect to the transferred energy and momentum, this…
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…
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 influence of $\Delta$ isobar components on the ground state properties of nuclear systems is investigated for nuclear matter as well as finite nuclei. Many-body wave functions, including isobar configurations, and binding energies are…
We study the role of the $\Delta$-isobar current on the response functions for high energy inclusive quasielastic electron scattering from nuclei. We consider a general Lagrangian which is compatible with contact invariance and perform a…
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…
Neutral current photon emission reactions with nucleons and nuclei are studied. These processes are important backgrounds for nu_mu to nu_e (bar(nu)_mu to bar(nu)_e) appearance oscillation experiments where electromagnetic showers…
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.…
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…
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…
Radiative nucleon-deuteron capture and two- and three-body photo disintegration of the three-nucleon bound state are described. The description uses the purely nucleonic charge-dependent CD-Bonn potential and its coupled-channel extension…
The excitation of a $\Delta$-isobar in a finite nucleus in charge--exchange ($^3\!$He,t) reaction is discussed in terms of a nuclear response function. The medium effects modifying a $\Delta$- and a pion propagation were considered for a…
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 pion-nucleon interaction in the P33 partial wave is assumed to proceed simultaneously through the excitation of the Delta-isobar and through a phenomenologically introduced non-resonant background potential. The introduction of the…
Electron-induced one-nucleon knock-out observables are computed for moderate to high momentum transfer making use of semi-relativistic expressions for the one-body and two-body meson-exchange current matrix elements. Emphasis is placed on…
Deuteron-proton elastic scattering is studied in the multiple scattering expansion formalism. The four contributions are taken into account: one-nucleon-exchange, single- and double scattering, and $\Delta$-isobar excitation. The presented…
Mechanisms of the charge exchange reaction $dp\to \{pp\}_{\!s} N\pi$, where $\{pp\}_{\!s}$ is a two-proton system at low excitation energy, are studied at beam energies 1 -- 2 GeV and for invariant masses $M_X$ of the final $N\pi $ system…