Precision measurements on trapped antihydrogen in the ALPHA experiment

Area of Science:

• Atomic Physics
• Antimatter Spectroscopy
• Fundamental Symmetries

Background:

• Trapped antihydrogen offers a unique system to test fundamental physics principles.
• Precision spectroscopy of antihydrogen is crucial for verifying symmetries between matter and antimatter.

Purpose of the Study:

• To perform high-precision measurements of spectral features in trapped antihydrogen.
• To test CPT (Charge-Parity-Time) invariance by comparing hydrogen and antihydrogen spectra.
• To explore future advancements in antihydrogen spectroscopy with enhanced facilities.

Main Methods:

• Observation of the 1S-2S transition in antihydrogen using two-photon laser excitation.
• Detailed measurement of the ground state hyperfine spectrum of antihydrogen.
• Utilizing trapped antihydrogen in the ALPHA experiment at CERN.

Main Results:

• The 1S-2S transition energy was determined with high precision, consistent with CPT invariance at 2×10^-10.
• The ground state hyperfine spectrum of antihydrogen was measured with a relative uncertainty of 4×10^-4.
• These results represent the most precise measurements of antihydrogen properties to date.

Conclusions:

• The measurements strongly support CPT invariance, a fundamental symmetry of nature.
• Current techniques achieve sensitivity at the few 100 kHz level, with prospects for further improvement.
• Future experiments with the ELENA facility will enable even more precise measurements of antihydrogen properties.