2014/03/31 by A. Miyazaki, T. Yamazaki, T. Suehara +7 · 1 citation
Engineering · Physics and Astronomy · #Advanced Frequency and Time Standards #Atomic and Molecular Physics #Gyrotron #Hyperfine structure #Muon and positron interactions and applications #Positronium #Resonance (particle physics) #Spectroscopy #hep-ex #physics.atom-ph #physics.ins-det
paper · pdf · doi:10.1093/ptep/ptu181
arxiv created 2014/12/17 · arxiv updated 2015/01/28 · openalex publication_date 2015/01/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report on the first measurement of the Breit-Wigner resonance of the transition from orthopositronium to para-positronium. We have developed an optical system to accumulate a power of over 20 kW using a frequency-tunable gyrotron and a Fabry-Prot cavity. This system opens a new era of millimeter-wave spectroscopy, and enables us to directly determine both the hyperfine interval and the decay width of para-Ps.