Dr Candadi V Sukumar

Abstract:

The cross section for an inclusive scattering process may be expressed in terms of a double path integral. Evaluation of the double path integral by the stationary-phase approximation yields classical equations of motion for the stationary trajectories and a classical cross section for the inclusive process which depends on the polarization of the initial state. Polarization analyzing powers are calculated from this theory and the results are compared with those obtained in an earlier paper. © 1995.

Abstract:

A semi-classical calculation is performed to predict spin polarisation observables for elastic heavy ion scattering of a quadrupole deformed projectile from a spinless target below the Coulomb barrier. A method introduced by Sukumar and Brink, based on a path integral formalism and a consistent quantum-mechanical treatment of both the relative motion and internal degrees of freedom is used. This method is an improvement on earlier semi-classical calculations based on the Alder and Winther method which, in the absence of excitation, predict cross-sections which are independent of the polarisation of the initial spin state. The expressions developed by Sukumar and Brink are evaluated to first order in the quadrupole moment of the projectile. Polarisation observables are compared to both quatum-mechanical coupled channels calculations and other approximate semi-classical calculations; good agreement is found. For backward angles, simple expressions for polarisation observables valid to first order in the quadrupole moment are given. © 1995.

Abstract:

In this article the connection between the τ functions of the Korteweg-de Vries (KdV) hierarchy and reflectionless potentials with an arbitrary number of bound states constructed using supersymmetric quantum mechanics is studied. It is shown how the underlying KdV flows can be extracted from the construction based on supersymmetric quantum mechanics. © 1995 American Institute of Physics.

Abstract:

The different causes that lead to polarisation effects in heavy-ion scattering are analysed. In semi-classical theories of heavy-ion reactions in which the relative motion is treated classically and the internal excitation by quantum mechanics there are no polarisation effects in the scattering if there is no absorption or inelastic scattering during the collision. A consistent quantum-mechanical treatment of both the relative motion and internal degrees of freedom is necessary to allow for the influence of the polarisation of the projectile on its relative motion with the target. In this paper the path integral method is used to calculate polarisation effects in heavy-ion reactions. It is shown that corrections to the primitive semi-classical propagator must be included to calculate the leading-order polarisation effects. Expressions for the analysing power are obtained. A simple model hamiltonian is used to illustrate the procedure. © 1993.