Speaker
Description
At the J-PARC muon facility (MUSE), we have launched a new project to precisely measure muon properties, such as magnetic moment, mass, and lifetime, by confining muons in a Penning trap.
In our experiment, high-intensity pulsed muons are slowed down before entering a Penning trap. Ultra-slow positive muons can be generated efficiently by laser ionization of thermal muonium. In a Penning trap, a $\pi$/2 pulse is applied to make muon spin orthogonal to the magnetic field and induce Larmor precession. From the time spectrum of muon decay, we can measure the magnetic moment of muon as well as the muon lifetime. In addition, if we measure the position of muon decay, muon mass can be estimated from cyclotron frequency.
We have already succeeded in trapping negative muons at MUSE H-line with a prototype setup. We aim at measuring the lifetime of negative muons confined in vacuum with better precision than the previous experiment [1]. Furthermore, we are investigating new techniques to slow down negative muons more efficiently, which is a key technique that improves muon trap efficiency, which would lead to antimuonium production. An overview of our project and the latest results will be presented.
[1] G. Bardin, et al., Phys Lett. 137B, 135 (1984).