DATE2022.07.04 #Awards & Prizes

Associate Professor Hiroyuki Torii, Department of Chemistry, received the 2021 Nishikawa Award from the High Energy Accelerator Science Faculty Council

Disclaimer: machine translated by DeepL which may contain errors.

Associate Professor Hiroyuki Torii

Associate Professor Hiroyuki Torii and his research group in the Department of Chemistry have received the 2021 Nishikawa Award from the High Energy Accelerator Science Encouragement Council for their "Study of Rabi Vibrational Spectroscopy in the Precision Measurement of Muonium Ultrafine Structure".

Torii and his research group have been studying precision spectroscopy of muonium, an exotic atom composed of positively charged muons (muons) and electrons. In conventional atomic spectroscopy, atoms are irradiated with electromagnetic waves, such as laser light, to measure the transition signal, and the frequency of the electromagnetic waves is changed to find the frequency at which resonance occurs. However, muons decay in an average lifetime of 2.2 microseconds, so muonium cannot be measured over time, limiting the accuracy of spectroscopy.

In the interaction between electromagnetic waves and atoms, "Rabi oscillations," in which periodic transitions are repeated between two levels of an atom near resonance, occur. Torii and his colleagues have developed and demonstrated a new method, "Rabi oscillation spectroscopy," to determine the resonance frequency with high precision by measuring the time variation of these Rabi oscillations over several microseconds. The new method can determine the resonance frequency more precisely than conventional methods, without any problem with variations in electromagnetic wave power. This is a major step forward in the verification of the Standard Model of quantum electrodynamics and elementary particles by muonium spectroscopy with the world's highest precision.

We congratulate Dr. Torii for winning this prize.

Nishikawa Prize
https://www.heas.jp/award/2021zyusyou.html

Press Release (August 2021)
https://www.s.u-tokyo.ac.jp/ja/press/2021/7502/

Science Youtube channel "Laboratory Door" (March 2022)
https://www.youtube.com/watch?v=sCelR8qalRI

(Responsibility: Professor Toshinori Mori, International Center for Elementary Particle Physics)