Dr Candadi V Sukumar

Abstract:

Vector polarization in a heavy-ion collision is influenced by coupling to inelastic channels. In the adiabatic approximation the coupling can be represented by an energy-independent induced spin-orbit interaction. The present paper presents a generalization which includes nonadiabatic effects as well as a contribution from the ground-state quadrupole moment. The derivation is based on second-order perturbation theory. The approximate effective spin-orbit potential includes the effects of the coupling to an inelastic channel for all values of the interaction time τ0. It reduces to the adiabatic approximation when τ0Δε/ℏ≫ 1 where Δε is the channel excitation energy. There is an application to the vector polarization observed in the scattering of 6Li and 7Li by 58Ni. © 2002 Elsevier Science B.V. All rights reserved.

Abstract:

An expression for the induced spin-orbit potential in a heavy-ion collision is derived by making an adiabatic approximation to the effective interaction in second-order perturbation theory. An explicit form for the induced spin-orbit interaction for the case of a projectile of arbitrary ground state spin S is given and is shown to be equivalent to the result obtained using the methods of geometrical magnetism. © 1999 Elsevier Science B.V.

Abstract:

Geometric magnetism is a term used for describing the leading corrections to the adiabatic approximation to a quantal system. In this paper we apply these ideas to a heavy ion collision and show that the leading correction to the static polarization potential is an induced spin-orbit interaction. We derive an explicit expression for its strength. © 1998 Elsevier Science B.V.

Abstract:

There is currently a great deal of experimental interest in the trapping of alkali-metal atoms in magnetic traps. In this Brief Report we present a method for calculating nonadiabatic spin-flip transitions in such traps. We show that for realistic traps currently being used the loss rate due to this mechanism is exponentially small. © 1997 The American Physical Society.

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.