Advances towards a new measurement of the 1S–2S transition of positronium

摘要

Abstract: In this paper, a new experiment is presented to measure the 1S–2S transition of positronium, the bound state ofnan electron and a positron. The goal is to improve the current accuracy by a factor of 5 to reach a precision of the ordernof 0.6 ppb, to check recent QED calculations. This accuracy is challenging, but it seems well within reach in view of thentechnological advances that have occurred during the last two decades. We will present the details of the experimental set-nup, the advances in the production of positronium, the developments of the laser system, and as well our new experimentalntechnique for the detection of Ps in the 2S state.