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.