1306.3810 (P. Bakule et al.)

Measurement of muonium emission from silica aerogel    [PDF]

P. Bakule, G. A. Beer, D. Contreras, M. Esashi, Y. Fujiwara, Y. Fukao, S. Hirota, H. Iinuma, K. Ishida, M. Iwasaki, T. Kakurai, S. Kanda, H. Kawai, N. Kawamura, G. M. Marshall, H. Masuda, Y. Matsuda, T. Mibe, Y. Miyake, S. Okada, K. Olchanski, A. Olin, H. Onishi, N. Saito, K. Shimomura, P. Strasser, M. Tabata, D. Tomono, K. Ueno, K. Yokoyama, S. Yoshida

Emission of muonium ($\mu^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distributions, follow general features expected from a diffusion process, while small deviations from a simple room-temperature thermal diffusion model are identified. The parameters of the diffusion process are deduced from the observed yields.

View original: http://arxiv.org/abs/1306.3810