Speaker
Description
Antihydrogen is an exciting tool for testing fundamental physics. Antihydrogen can reproducibly be synthesized and trapped in the laboratory for extended periods of time [1][2], offering an opportunity to study its properties with high precision. Of particular interest is the two-photon 1S-2S transition, due to the staggering precision of which it has been measured in hydrogen [3]. Since only a relatively small number of antihydrogen atoms are available, spectroscopy techniques must take advantage of the high efficiency at which matter-antimatter annihilations can be detected. I will discuss how experimental methods have been developed by the ALPHA collaboration to first observe [4] and later characterise [5] the 1S-2S transition in antihydrogen, and how hydrogen-like precision may soon be within reach.
[1] G. B. Andresen et al. (ALPHA collaboration). Trapped Antihydrogen. Nature 468, 673-676 (2010).
[2] G. B. Andresen et al. (ALPHA collaboration). Confinement of antihydrogen for 1,000 seconds. Nature Physics 7, 558–564 (2011)
[3] C. G. Parthey et al. Improved Measurement of the Hydrogen 1S - 2S Transition Frequency. Phys. Rev. Lett. 107, 203001 (2011).
[4] M. Ahmadi et al. (ALPHA collaboration). Observation of the 1S-2S Transition in Trapped Antihydrogen. Nature 541, 506-510 (2017).
[5] M. Ahmadi et al. (ALPHA collaboration). Characterization of the 1S-2S Transition in Antihydrogen. Nature 557, 71-75 (2018).
