TORII Hiroyuki

TORII Hiroyuki
Associate Professor
Department of Chemistry (UG), Department of Chemistry (GR), Graduate School of Science
E-mail torii (at)
Room Science Bldg., Room B283

Research Field

Exotic Atom Physics, Radiation Sciences

Research Subject

Microwave Spectroscopy of Muonium and Muonic Atoms, Radiation Management & Education, Analytic Research on Scientific Communication of Radiation Risks

Current Research

We perform microwave spectroscopy of the hyperfine structure of the muonium atom (an exotic atom composed of a positive muon and an bound electron) and muonic atoms (where one of the electrons of a normal atom is replaced by a negative muon), aiming at precise determination of the magnetic moment and thus the mass of the muon, which results in the test of fundamental laws of physics as well as search for new physics and possible trace of new particles.
Another topic of interest is radiation education and scientific communication of radiation risks. We study how scientific information can by effectively disseminated to the public in the era of social media, by analyzing Twitter (X) big data after the Fukushima nuclear power plant accident.


Muon, Muonium Atom, Muonic Atom, Exotic Atom, Antiproton, Radiation, Twitter Data Analysis, Risk Communication, Science Communication