The quest for precision spectroscopy and gravity measurements of antihydrogen atoms

by Prof. Elazar Sarid

Ben Gurion University of the Negev

at Physics Colloquium

Tue, 18 Jun 2024, 15:15
Ilse Katz Institute for Nanoscale Science & Technology (51), room 015

Abstract

Comparison of the properties of matter and antimatter is an important basic physics problem. The latest achievement is the successful measurement of gravitational free fall of neutral antihydrogen atoms, demonstrating that they actually fall down (1). This was achieved in ALPHA-g, a new vertical trap at CERN.
Measurements of energy transitions in trapped antihydrogen and their comparison to the transitions in hydrogen atoms is a sensitive test of CPT symmetry. Since the first trapping of antihydrogen atoms [2], the ALPHA collaboration in CERN performed a series of precision spectroscopic measurements characterizing its energy levels. Measurement of the transition 1S→2S in antihydrogen, using two-photon laser excitation with 243 nm light [3] indicated that the transition energy is equal to its hydrogen counterpart at the level of about 2×10-12. We also measured the fine structure of the 2S-2P levels [4] and the hyperfine splitting of the ground state [5]. Further improvements are foreseen as we implement new techniques such as laser cooling of the antihydrogen atoms [6].

[1] Observation of the effect of gravity on the motion of antimatter, Nature 621, 717 (2023)
[2] Trapped Antihydrogen, Nature 468,673 (2010)
[3] Characterization of the 1S–2S transition in antihydrogen, Nature 557, 71 (2018)
[4] Investigation of the fine structure of antihydrogen, Nature 578, 375 (2020)
[5] Observation of the hyperfine spectrum of antihydrogen, Nature 548, 66 (2017)
[6] Laser cooling of antihydrogen, Nature 592, 35 (2021)

Created on 08-04-2024 by Maniv, Eran (eranmaniv)
Updaded on 06-06-2024 by Maniv, Eran (eranmaniv)