Nonperturbative Techniques for QED Bound States

Abstract

Advantages of using a low-energy effective theory to study bound state properties are briefly discussed, and a nonperturbative implementation of such an effective theory is described within the context of nonrelativistic quantum mechanics. The hydrogen atom, in the approximation of a structureless, infinite-mass nucleus, but with the leading relativistic and radiative corrections included, is used to demonstrate the construction and solution of the effective theory. The resulting Hamiltonian incorporates a finite ultraviolet cutoff and can be solved nonperturbatively. An appendix lists explicit formulae for the various matrix elements necessary to diagonalize the Hamiltonian using gaussian basis sets.

arXiv comment11 pages. Talk presented at the MRST conference, U. of Rochester, 8-9 May 2000, to appear in the proceedings