A study is made of polarized deuteron elastic scattering from 58Ni and 40Ca at the intermediate energies of 400 and 700 MeV. A three-body formalism, based on the Single Folding Model, is used for two sets of Dirac nucleon optical potential parameters. Both potentials are designed to fit the proton elastic scattering observables at half the incident deuteron energy. The two potentials give different predictions for the deuteron scattering observables when used in the Schrodinger equation with relativistic kinematics. Good qualitative agreement with the experimental observables is obtained in both cases for deuteron elastic cross-section, vector (Ay) and tensor (Ayy) analyzing power data of the Saclay group. Quantitative discrepancies between theory and data, particularly in Ayy, suggest mechanisms missing from the simple three-body model. To this end, two sources of spin-dependent effects, Pauli-blocking and breakup of the deuteron to spin-singlet intermediate states, are studied. The role of the spin-dependence associated with Pauli-blocking is studied quantitatively for the d-58 Ni system. The magnitude of the momentum-dependent Tp tensor interaction, is shown to pass through a local maximum in the region of 400 MeV incident deuteron energy. Comparison of numerical calculations with the available experimental data at this energy shows the Pauli mechanism not to be responsible for outstanding discrepancies between theory and data. Breakup effects on the elastic amplitude are studied within a two-step calculation, using two separate high energy methods. The first neglects distortion in the initial, final and intermediate states. Use is made of the Adiabatic approximation, which allows closure over the intermediate breakup states. The effect on the elastic amplitude due to breakup to both triplet and singlet intermediate spin states are calculated. The inclusion of spin-singlet breakup in the model has a very large effect on Ayy, compared with that of spin-triplet breakup. This is attributed to a large contribution from a TL-like tensor interaction in the case of singlet breakup, which is negligibly small in the triplet case. Second order breakup effects are also calculated in Glauber theory, using central potentials. Continuum-continuum coupling effects are found to be negligible at intermediate energies, and thus the two-step calculation is adequate. Glauber theory shows, however, that distortion effects are important at these energies, and suggests the need for a more accurate treatment of spin-singlet breakup effects in future calculations.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:328117 |
| Date | January 1989 |
| Creators | Al-Khalili, Jameel Sadik |
| Publisher | University of Surrey |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://epubs.surrey.ac.uk/842863/ |
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