1. Measurement of the proton Zemach radius from the hyperfine splitting in muonic hydrogen atom
- Author
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Shinji Okada, Kazuo S. Tanaka, Yasuyuki Matsuda, M. Iwasaki, S. Kanda, Norihito Saito, Yu Oishi, Shuu Aikawa, A. Takamine, Hideki Ueno, Katsumi Midorikawa, M. Sato, Masaki Yumoto, Katsuhiko Ishida, Yue Ma, and Satoshi Wada
- Subjects
Physics ,History ,Muon ,Proton ,Radius ,Hydrogen atom ,Computer Science Applications ,Education ,Lamb shift ,Charge radius ,Atom ,Physics::Atomic Physics ,Atomic physics ,Bohr radius - Abstract
Muonic hydrogen is a bound state of a proton and a negative muon. Its Bohr radius is 200 times smaller than that of an electronic hydrogen atom. Therefore, a spectroscopy of the muonic hydrogen is highly sensitive to the finite size effect of proton. Recent years, the proton charge radius was determined by the laser spectroscopy of the Lamb shifts in muonic hydrogen atom. The experiment determined the proton charge radius significantly smaller than the results of past measurements. This anomaly is called “proton radius puzzle” and it has been an important unsolved problem in subatomic physics. Towards solving the puzzle, a new measurement of the ground-state hyperfine splitting in muonic hydrogen was proposed. The hyperfine splitting of muonic hydrogen derives the proton Zemach radius, which is defined as a convolution of the charge distribution with the magnetic moment distribution. This experiment aims to determine the proton Zemach radius with 1% precision by a measurement of the decay electron angular asymmetry. In order to test the feasibility of the laser spectroscopy, a preliminary experiment to measure the hyperfine quenching rate was proposed.
- Published
- 2018