Model wave functions and dynamic correlations in light-medium nuclei

The nuclei $^4$He, $^8$Be, $^{12}$C and $^{16}$O have been studied starting from nucleon-nucleon interactions of $v_4$ type. The wave function is built as the product of three terms, a Jastrow correlation factor, a linear correlation factor and a model wave function. The correlation factors account for both the short range repulsive and the spin and isospin dependence of the nuclear potential. The model wave function is antisymmetric and has the values of the angular momentum and parity of the state under description. For the model wave function we have used two different schemes. The first one is based on a Harmonic Oscillator shell model with and without deformation, and the second one is based on the Margenau-Brink model of alpha clustering. Projection operators of parity and total angular momentum are used. The performance of these two models is studied and compared systematically. Wave functions for the ground state and some members of its rotational band and some other bound states of these nuclei have been obtained. Binding energies, root mean square radius and the expectation value of the kinetic energy and the different channels of the nuclear interactions and the one-- and two-- body densities are reported. The two different model wave functions and the effects of the different nucleon-nucleon correlations have been evaluated on those quantities. All the results here presented have been obtained by using the Variational Monte Carlo method.