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A. D. Alhaidari

Publications and source records attributed to A. D. Alhaidari.

At least 127 records · Page 7Linked to original sources
arXiv2003

The Relativistic Dirac-Morse Green's function

Using a recently developed approach for solving the three dimensional Dirac equation with spherical symmetry, we obtain the two-point Green's function of the relativistic Dirac-Morse problem. This is accomplished by setting up the relativistic problem in such a way that makes comparison with the nonrelativistic problem highly transparent and results in a mapping of the latter into the former. The relativistic bound states energy spectrum is easily obtained by locating the energy poles of the Green's function components in a simple and straightforward manner.

hep-th↗
arXiv2003

On the relativistic two-point Green's function

Using a recently developed approach for solving the three dimensional Dirac equation with spherical symmetry, we obtain simple representations for the Green's function of the Dirac-Oscillator and Dirac-Coulomb problems. This is accomplished by setting up the relativistic problem in such a way that makes comparison with the nonrelativistic problem highly transparent and results in a map of the latter into the former. An advantage of this representation is in the computational economy as depicted by the number of terms, which are quadratic in the Whittaker functions. These are single terms except for the off-diagonal elements of the Dirac-Coulomb Green's function which, nonetheless, simplifies into the sum of a first order and third order relativistic terms.

math-ph↗
arXiv2003

Solution of the Dirac Equation for Potential Interaction

An effective approach for solving the three-dimensional Dirac equation for spherically symmetric local interactions, which we have introduced recently, is reviewed and consolidated. The merit of the approach is in producing Schrodinger-like equation for the spinor components that could simply be solved by correspondence with well-known exactly solvable non-relativistic problems. Taking the nonrelativistic limit will reproduce the nonrelativistic problem. The approach has been used successfully in establishing the relativistic extension of all classes of shape invariant potentials as well as other exactly solvable nonrelativistic problems. These include the Coulomb, Oscillator, Scarf, Poschl-Teller, Woods-Saxon, etc.

math-ph↗
arXiv2003

Nonrelativistic Green's function for systems with position-dependent mass

Given a spatially dependent mass we obtain the two-point Green's function for exactly solvable nonrelativistic problems. This is accomplished by mapping the wave equation for these systems into well-known exactly solvable Schrodinger equations with constant mass using point canonical transformation. The one-dimensional oscillator class is considered and examples are given for several mass distributions.

cond-mat↗
arXiv2002

Solutions of the nonrelativistic wave equation with position-dependent effective mass

Given a spatially dependent mass distribution we obtain potential functions for exactly solvable nonrelativistic problems. The energy spectrum of the bound states and their wavefunctions are written down explicitly. This is accomplished by mapping the wave equation for these systems into well-known exactly solvable Schrodinger equations with constant mass using point canonical transformation. The Oscillator, Coulomb, and Morse class of potentials are considered.

quant-ph↗
arXiv2002

Deformation of the J-matrix method of scattering

We construct nonrelativistic J-matrix theory of scattering for a system whose reference Hamiltonian is enhanced by one-parameter linear deformation to account for nontrivial physical effects that could be modeled by a singular ground state coupling.

math-ph↗
arXiv2002

Relativistic shape invariant potentials

Dirac equation for a charged spinor in electromagnetic field is written for special cases of spherically symmetric potentials. This facilitates the introduction of relativistic extensions of shape invariant potential classes. We obtain the relativistic spectra and spinor wavefunctions for all potentials in one of these classes. The nonrelativistic limit reproduces the usual Rosen-Morse I & II, Eckart, Poschl-Teller, and Scarf potentials.

hep-th↗
arXiv2002

Solution of the relativistic Dirac-Morse problem

Dirac equation for a charged particle in static electromagnetic field is written for special cases of spherically symmetric potentials. Besides the well known Dirac-Coulomb and Dirac-Oscillator potentials, we obtain a relativistic version of the S-wave Morse potential. This is accomplished by adding a simple exponential potential term to the Dirac operator, which in the nonrelativistic limit reproduces the usual Morse potential. The relativistic bound states spectrum and spinor wavefunctions are obtained.

hep-th↗
arXiv2002

Scattering phase shift for relativistic separable potential with Laguerre-type form factors

As an extension of earlier work [J. Phys. A: Math. Gen. 34 (2001) 11273] we obtain analytic expressions for the scattering phase shift of M-term relativistic separable potential with Laguerre-type form factors and for M = 1, 2, and 3. We take the Dirac Hamiltonian as the reference Hamiltonian. Just like in the cited article, the tools of the relativistic J-matrix method of scattering will be used. However, the results obtained here are for a general angular momentum, which is in contrast to the previous work where only S-wave scattering could be calculated. An exact numerical evaluation for higher order potentials (M >= 4) can be obtained in a simple and straightforward way.

math-ph↗
arXiv2001

The relativistic J-matrix theory of scattering: an analytic solution

The relativistic J-matrix is investigated in the case of Coulomb-free scattering for a general short-range spin-dependent perturbing potential and in two different L2 bases. The resulting recursion relation of the reference problem, in this case, has an analytic solution. The non-relativistic limit is obtained and shown to be identical to the familiar non-relativistic J-matrix. Scattering examples are given to verify the non-relativistic limit and calculate the relativistic effects in the phase shift.

hep-th↗
arXiv2001

Scattering phase shift for relativistic exponential-type separable potentials

The J-matrix method of scattering is used to obtain analytic expressions for the phase shift of two classes of relativistic exponential-type separable potentials whose radial component is either of the general form r^(n-1)exp(-r) or r^(2n)exp(-r^2), where n = 0, 1, or 2. The rank of these separable potentials is n + 1. The nonrelativistic limit is obtained and shown to be identical to the nonrelativistic phase shift. An exact numerical evaluation for higher order potentials (n > 2) can also be obtained in a simple way as illustrated for the case n = 3.

math-ph↗
arXiv2001

Graded extension of SO(2,1) Lie algebra and the search for exact solutions of Dirac equation by point canonical transformations

SO(2,1) is the symmetry algebra for a class of three-parameter problems that includes the oscillator, Coulomb and Morse potentials as well as other problems at zero energy. All of the potentials in this class can be mapped into the oscillator potential by point canonical transformations. We call this class the "oscillator class". A nontrivial graded extension of SO(2,1) is defined and its realization by two-dimensional matrices of differential operators acting in spinor space is given. It turns out that this graded algebra is the supersymmetry algebra for a class of relativistic potentials that includes the Dirac-Oscillator, Dirac-Coulomb and Dirac-Morse potentials. This class is, in fact, the relativistic extension of the oscillator class. A new point canonical transformation, which is compatible with the relativistic problem, is formulated. It maps all of these relativistic potentials into the Dirac-Oscillator potential.

math-ph↗