Quantum electrodynamics recent progress

This experimental development was matched by rapid theoretical progress, and the comparison and interplay between theory and experiment has been important in the field of metrology, leading to higher precision in the determination of the fundamental constants. We feel that now is a good time to review modern bound state theory. The theory of hydrogenic bound states is widely described in the literature. The basics of nonrelativistic theory are contained in any textbook on quantum mechanics, and the relativistic Dirac equation and the Lamb shift are discussed in any textbook on quantum electrodynamics and quantum field theory. An excellent source for the early results is the classic book by Bethe and Salpeter [6]. A number of excellent reviews contain more recent theoretical results, and a representative, but far from exhaustive, list of these reviews includes [7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]. 

Abstract. We report progress towards making a precise measurement of the 2S Lamb shift in singly-ionised helium by spectroscopy of the 2S-3S transition. The motivation for the experiment is discussed with reference to recent developments in the theory of quantum electrodynamics (QED) and a description of the apparatus and techniques used is given. 

One- and two-electron atoms provide the traditional testing ground for the techniques of atomic physics. Since highly accurate electronic wave functions are obtainable, high precision comparisons between theory and experiment can be made. Much of the current research interest centers on relativistic and quantum electrodynamic (QED) effects in highly ionized systems. The purpose of the present paper is to summarize recent progress in this area. 

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