=Date and Place=
Nov.26th(Tue.) 13:30~ at RIBF Hall
Dr. Kanda, Sohtaro
(Iwasaki Meson Science Laboratory, RIKEN Nishina Center)
Precision microwave spectroscopy of the ground-state hyperfine splitting in muonium atom
A hydrogen-like atom consisting of a positive muon and an electron is known as muonium. It is an ideal two-body system for a precision test of the bound-state QED theory and fundamental symmetries. In this seminar, a new precision measurement of the muonium ground-state hyperfine splitting (HFS) will be presented. The measuring precision of the muonium HFS had been statistically limited by a conventional method with the continuous muon beam. The experiment was the first trial of muonium spectroscopy with the high-intensity pulsed muon beam at J-PARC. To resolve the problems in the precursor experiments, the world's highest intensity pulsed muon beam, a high-rate capable positron detector, two-dimensional and three-dimensional muon beam profile monitors, and a large-volume magnetic shield were orchestrated. In the pursuit of evaluation of the systematic uncertainty, a numerical simulation framework was developed. As a result of the experiment, the resonance of the hyperfine transition was successfully observed. Experimental data analysis and estimation of systematic uncertainty demonstrated the validity of the new methodology seeking a new frontier of the precision physics with the high-intensity pulsed muon beam.