Formation Of Lightest Muonic Atoms In Low-Density Gases

A novel technique devised to produce light muonic atoms efficiently in low pressure gases (10 to 600 torr at 300 K) has been successfully implemented in helium. Muons produced by in-flight decay of 40 MeV/ c pions are trapped in a magnetic bottle filled with the low density gas. The high-yield formation of muonic atoms is demonstrated by detecting the characteristic X-rays as well as the μ-decay electrons.