T Pask et al 2008 J. Phys. B: At. Mol. Opt. Phys. 41 081008 doi:10.1088/0953-4075/41/8/081008
T Pask1, D Barna2,3, A Dax2, R S Hayano2, M Hori2,5, D Horváth3,4, B Juhász1, C Malbrunot1,6, J Marton1, N Ono2, K Suzuki1, J Zmeskal1 and E Widmann1
Show affiliationsWe 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 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 5 and reduced the linewidth by a factor of 3 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.
36.10.Gv Mesonic, hyperonic and antiprotonic atoms and molecules
32.10.Fn Fine and hyperfine structure
32.70.Jz Line shapes, widths, and shifts
Issue 8 (28 April 2008)
Received 4 March 2008, in final form 13 March 2008
Published 3 April 2008
T Pask et al 2008 J. Phys. B: At. Mol. Opt. Phys. 41 081008
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