International Conference on Exotic Atoms and Related Topics - EXA2014

Recently the CREMA collaboration(*) succeeded to measure the Lamb shift (2S-2P energy difference) in muonic hydrogen by means of laser spectroscopy, providing a ten times more accurate value for the charge radius of the proton [1,2]. This study analyzes the data sets taken with muonic hydrogen and muonic deuterium even further in order to investigate the deexcitation of the metastable 2S-state in both isotopes. In this effort the population and lifetime of atoms undergoing collisional quenching to the 2P-state was measured. Additionally we observe radiative deexcitation of so called "long-lived" 2S-states in muonic deuterium that is interpreted as formation and successive decay of excited muonic molecules [3]. (*) Charge Radius Experiment using Muonic Atoms [1] R. Pohl et al. (CREMA coll.), Nature 466, 213 (2010) [2] A. Antognini et al. (CREMA coll.), Science 339, 417 (2013). [3] M. Diepold et al. (CREMA coll.), Phys. Rev. A 88, 042520 (2013)