An effective two-body density operator for point nucleon system folded with two-body correlation functions, which take account of the effect of the strong short range repulsion and the strong tensor force in the nucleon-nucleon forces, is produced and used to study the ground state two-body charge density distributionsare in opposite direction to those of SRC.

An expression for the transition charge density is investigated where the deformation in nuclear collective modes is taken into consideration besides the shell model transition density. The inelastic longitudinal form factors C2 calculated using this transition charge density with excitation of the levels for Cr54,52,50 nuclei. In this work, the core polarization transition density is evaluated by adopting the shape of Tassie model together with the derived form of the ground state two-body charge density distributions (2BCDD's). It is noticed that the core polarization effects which represent the collective modes are essential in obtaining a remarkable agreement between the calculated inelastic longitudinal F(q)'s and those of experimental data.

The two-neutron halo-nuclei (17B, 11Li, 8He) was investigated using a two-body nucleon density distribution (2BNDD) with two frequency shell model (TFSM). The structure of valence two-neutron of 17B  nucleus in a pure (1d5/2) state and in a pure (1p1/2) state for  11L and 8He nuclei. For our tested nucleus, an efficient (2BNDD's) operator for point nucleon system folded with two-body correlation operator's functions was used to investigate nuclear matter density distributions, root-mean square (rms) radii, and elastic electron scattering form factors. In the nucleon-nucleon forces the correlation took account of the effect for the strong tensor force (TC's). The wave functions of single particle harmonic oscillator are used with two different oscillator size parameters βc and βv, where the former is for the core (inner) orbits and the latter is for the valence (halo) orbits. The measured matter density distributions of these nuclei clearly showed long tail results. To investigate elastic electron scattering form factors the plane wave born approximation (PWBA) with two body nucleon density distribution (2BNDD's) was use.

The nucleon momentum distributions ( NMD ) for the ground state and elastic electron scattering form factors have been calculated in the framework of the coherent fluctuation model and expressed in terms of the weight function (fluctuation function). The weight function has been related to the nucleon density distributions of nuclei and determined from theory and experiment. The nucleon density distributions( NDD ) is derived from a simple method based on the use of the single particle wave functions of the harmonic oscillator potential and the occupation numbers of the states. The feature of long-tail behavior at high momentum region of the NMD has been obtained using both the theoretical and experimental weight functions. IntroductionThe study of momentum wave functions is a powerful tool in studying the ground state properties of nuclei, particularly the momentum distribution of nucleons. The quantitative knowledge of the momentum distribution is very important for revealing the proper mechanism of the nuclear reactions and for their complete description and also it is important in studying the bulk properties of the nucleus such as: total binding and kinetic energies and many other properties of the nucleus [1]. At present, there is no method for directly measuring the NMD in nuclei. The quantities that are measured by particlenucleus and nucleus-nucleus collisions are the cross sections of different reactions, and these contain information on the NMD of target nucleons. The experimental evidence obtained from inclusive and exclusive electron scattering on nuclei established the existence of long-tail behavior of the NMD at high momentum region (

An Expression for the transition charge density is investigated where the deformation in nuclear collective modes is taken into consideration besides the shell model transition density. The inelastic longitudinal form factors C2 are calculated using this transition charge density with excitation of the levels in B MeV. In this work, the core polarization transition density is evaluated by adopting the shape of Tassie model togther with the derived form of the ground state two-body charge density distributions (2BCDD's). It is noticed that the core polarization effects which represent the collective modes are essential in obtaining the remarkable agreement between the calculated inelastic longitudinal F(q)'s and those of experimental data.