Speaker
Description
We describe laser spectroscopy of the 1S-2S transition in trapped [1] and laser cooled [2] antihydrogen to 13 significant figures [3] and a lineshape theory [4] for its analysis. This is an order of magnitude improvement over our last results [5]. We discuss the extension of the methods to allow spectroscopy of hydrogen in the same apparatus as proposed in [6] and with a proof-of-principle with antihydrogen [7]. Addressing both atoms under the same conditions will minimize many systematic effects — such as the AC Stark shift and magnetic and electric fields besides sidereal localization — and will allow a direct comparison of the CPT conjugated species to 15 or more digits. The techniques have direct implications on tests of the Charge-Parity-Time (CPT) Symmetry, searching for explanations on the mystery of matter-antimatter asymmetry in the universe. The gravitational fall of antihydrogen [8], following an original proposal by the speaker [9] will be briefly discussed.
[1] G. Andresen et al. [ALPHA Collab.],Trapped antihydrogen, Nature 468, 673(2010)
[2] C. Baker et al. [ALPHA Collab.], Laser cooling of antihydrogen atoms, Nature 592, 35(2021)
[3] [ALPHA Collab.], manuscript under preparation
[4] L. Azevedo and C. Lenz Cesar, Quasianalytical line shape for the 1S-2S laser spectroscopy of antihydrogen and hydrogen, Phys. Rev. A 111, 012807 (2025)
[5] M. Ahmadi et al. [ALPHA Collab.], Characterization of the 1S–2S transition in antihydrogen, Nature 557, 71 (2018)
[6] C. Lenz Cesar, A sensitive detection method for high resolution spectroscopy of trapped antihydrogen, hydrogen and other trapped species, J. Phys. B: At., Mol. Opt. Phys. 49, 074001 (2016)
[7] [ALPHA Collab.], manuscript under preparation
[8] E. K. Anderson, et al. [ALPHA Collab.], Observation of the effect of gravity on the motion of antimatter, Nature 621, 716 (2023)
[9] C. L. Cesar, Trapping and spectroscopy of hydrogen. Hyp. Interact. 109, 293 (1997)
