First observation of o-Ps to p-Ps transition and first direct measurement of positronium hyperfine splitting with sub-THz light
/ Authors
T. Yamazaki, A. Miyazaki, T. Suehara, T. Namba, S. Asai, Tomio Kobayashi, H. Saito, Y. Urushizaki, I. Ogawa, T. Idehara
and 1 more author
/ Abstract
Positronium is an ideal system for the research of the bound state QED. The hyperfine splitting of positronium (Ps-HFS, about 203 GHz) is an important observable but all previous measurements of Ps-HFS had been measured indirectly using Zeeman splitting. There might be the unknown systematic errors on the uniformity of magnetic field. We are trying to measure Ps-HFS directly using sub-THz radiation. We developed an optical system to accumulate high power (about 10 kW) radiation in a Fabry-Pérot resonant cavity and observed the positronium hyperfine transition for the first time.
Journal: Hyperfine Interactions