الفهرس 
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Abstract
Within the formalism of the Glauber multiple scattering theory (GMST),
High-energy elastic collisions between light and medium weight nuclei (A, B ≥ 4) are investigated by accounting for the full multiple scattering series(contains 2 A*B - 1 terms) of the Glauber amplitude and treating the effect of the center – of – mass (c.m.) correlations consistently. For the first purpose: a formula for the scattering amplitude, more practical in calculations, is developed by assuming cluster structures for the colliding nuclei and classifying the terms of multiple scattering series with the aid of the theory of permutation groups. Gaussian forms for the nuclear densities and nucleon-nucleon (NN) scattering amplitudes, we derived analytic formulas for the nuclear and Coulomb phase-shift functions. For the second purpose, we incorporated the effect of the c.m. correlations in the phase-shift functions with the same order as the scattering terms. The total (nuclear + Coulomb) differential cross sections for the elastic collisions; α-α at incident energies 1.98, 2.57 and 4.2 GeV, α- 12C at 1.37 and 4.2 GeV, 12C- 12C at 1.016 and 1.44 GeV, 16O- 12C at 1.503 GeV and l6O – 16O at 0.704 GeV, are calculated and the results are compared with the available experimental data. In comparison with the previous calculations (where the full multiple scattering series is truncated), our results showed that, the inclusion of all higher order multiple scattering terms gives a considerable improvement in fitting the experimental data at large scattering angles .The effect of invoking a phase-variation in the NN scattering amplitude is also examined in these calculations and we found that introducing such phase has improved our results, especially at the minima of the diffraction pattern in comparison with the free-phase calculations.
The details of the study contained in each chapter of this thesis are proceeded as follows:-
In chapter 1, we surveyed the previous investigations made in the framework of GMST to study the nucleus-nucleus elastic scattering at high energies.
In chapter 2, using double Gaussian density consistent with the electron scattering experiments, we obtained analytical expressions for the nuclear and coulomb phase-shift functions, while the effect of the cm. correlations is approximated to a global correction multiplied by the scattering amplitude. The angular distributions of the above reactions are calculated using this analysis and the results obtained are discussed with respect to the previous optical limit calculations (where the single scattering terms are only considered).
In chapter 3 , an exact cm. correlation function using a single-Gaussian type for the nuclear density is incorporated in each order of the expansion of the phase-shift functions. As a result, the correlated nuclear and Coulomb phase-shift functions have new analytic expressions that contain the uncorrelated ones. The angular distributions are also calculated with the correlated and uncorrelated phase-shift functions and a comparison is made between them. Finally, to manifest the significance of the developments made in this thesis, comparison is made with the results obtained using similar fourth order Calculation [19].