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The role of three-body forces in few-body systemsMasita, Dithlase Frans 25 August 2009 (has links)
Bound state systems consisting of three nonrelativistic particles are numerically
studied. Calculations are performed employing two-body and three-body forces as
input in the Hamiltonian in order to study the role or contribution of three-body
forces to the binding in these systems. The resulting differential Faddeev equations
are solved as three-dimensional equations in the two Jacobi coordinates and the
angle between them, as opposed to the usual partial wave expansion approach. By
expanding the wave function as a sum of the products of spline functions in each of
the three coordinates, and using the orthogonal collocation procedure, the equations
are transformed into an eigenvalue problem.
The matrices in the aforementioned eigenvalue equations are generally of large order.
In order to solve these matrix equations with modest and optimal computer memory
and storage, we employ the iterative Restarted Arnoldi Algorithm in conjunction
with the so-called tensor trick method. Furthermore, we incorporate a polynomial
accelerator in the algorithm to obtain rapid convergence. We applied the method
to obtain the binding energies of Triton, Carbon-12, and Ozone molecule. / Physics / M.Sc (Physics)
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The role of three-body forces in few-body systemsMasita, Dithlase Frans 25 August 2009 (has links)
Bound state systems consisting of three nonrelativistic particles are numerically
studied. Calculations are performed employing two-body and three-body forces as
input in the Hamiltonian in order to study the role or contribution of three-body
forces to the binding in these systems. The resulting differential Faddeev equations
are solved as three-dimensional equations in the two Jacobi coordinates and the
angle between them, as opposed to the usual partial wave expansion approach. By
expanding the wave function as a sum of the products of spline functions in each of
the three coordinates, and using the orthogonal collocation procedure, the equations
are transformed into an eigenvalue problem.
The matrices in the aforementioned eigenvalue equations are generally of large order.
In order to solve these matrix equations with modest and optimal computer memory
and storage, we employ the iterative Restarted Arnoldi Algorithm in conjunction
with the so-called tensor trick method. Furthermore, we incorporate a polynomial
accelerator in the algorithm to obtain rapid convergence. We applied the method
to obtain the binding energies of Triton, Carbon-12, and Ozone molecule. / Physics / M.Sc (Physics)
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Bound states for A-body nuclear systemsMukeru, Bahati 03 1900 (has links)
In this work we calculate the binding energies and root-mean-square radii for A−body
nuclear bound state systems, where A ≥ 3. To study three−body systems, we employ
the three−dimensional differential Faddeev equations with nucleon-nucleon semi-realistic
potentials. The equations are solved numerically. For this purpose, the equations are
transformed into an eigenvalue equation via the orthogonal collocation procedure using
triquintic Hermite splines. The resulting eigenvalue equation is solved using the Restarted
Arnoldi Algorithm. Ground state binding energies of the 3H nucleus are determined.
For A > 3, the Potential Harmonic Expansion Method is employed. Using this method,
the Schr¨odinger equation is transformed into coupled Faddeev-like equations. The Faddeevlike
amplitudes are expanded on the potential harmonic basis. To transform the resulting
coupled differential equations into an eigenvalue equation, we employ again the orthogonal
collocation procedure followed by the Gauss-Jacobi quadrature. The corresponding
eigenvalue equation is solved using the Renormalized Numerov Method to obtain ground
state binding energies and root-mean-square radii of closed shell nuclei 4He, 8Be, 12C, 16O
and 40Ca. / Physics / M. Sc. (Physics)
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Bound states for A-body nuclear systemsMukeru, Bahati 03 1900 (has links)
In this work we calculate the binding energies and root-mean-square radii for A−body
nuclear bound state systems, where A ≥ 3. To study three−body systems, we employ
the three−dimensional differential Faddeev equations with nucleon-nucleon semi-realistic
potentials. The equations are solved numerically. For this purpose, the equations are
transformed into an eigenvalue equation via the orthogonal collocation procedure using
triquintic Hermite splines. The resulting eigenvalue equation is solved using the Restarted
Arnoldi Algorithm. Ground state binding energies of the 3H nucleus are determined.
For A > 3, the Potential Harmonic Expansion Method is employed. Using this method,
the Schr¨odinger equation is transformed into coupled Faddeev-like equations. The Faddeevlike
amplitudes are expanded on the potential harmonic basis. To transform the resulting
coupled differential equations into an eigenvalue equation, we employ again the orthogonal
collocation procedure followed by the Gauss-Jacobi quadrature. The corresponding
eigenvalue equation is solved using the Renormalized Numerov Method to obtain ground
state binding energies and root-mean-square radii of closed shell nuclei 4He, 8Be, 12C, 16O
and 40Ca. / Physics / M. Sc. (Physics)
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