Improved Study of the Antiprotonic Helium Hyperfine Structure

Abstract

We report the initial results from a systematic study of the hyperfine (HF) structure of antiprotonic helium (n,l) = (37,~35) carried out at the Antiproton Decelerator (AD) at CERN. We performed a laser-microwave-laser resonance spectroscopy using a continuous wave (cw) pulse-amplified laser system and microwave cavity to measure the HF transition frequencies. Improvements in the spectral linewidth and stability of our laser system have increased the precision of these measurements by a factor of five and reduced the line width by a factor of three compared to our previous results. A comparison of the experimentally measured transition frequencies with three body QED calculations can be used to determine the antiproton spin magnetic moment, leading towards a test of CPT invariance.

14 pages 9 figures

References in corpus (1)

• Hyperfine structure of antiprotonic helium revealed by a laser-microwave-laser resonance method

Cited by in corpus (6)

• Observation of Spin Flips with a Single Trapped Proton
• Physics at CERN's Antiproton Decelerator
• Antiproton magnetic moment determined from the HFS of antiprotonic helium
• First observation of two hyperfine transitions in antiprotonic He-3
• Microwave spectroscopic study of the hyperfine structure of antiprotonic helium-3
• Spin-orbit corrections of order $m{\alpha }^6$ to the fine structure of $(37,35)$ state in ${}^4{He}^{+}\bar{p}$ atom