1. Muon Science Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
2. Meson Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801 Japan
3. Department of Radioisotopes, Japan Atomic Energy Research Institute (JAERI), 2-4 Shirane, Tokai, Ibaraki, 319-1195 Japan
4. Department of Radiation Research for Environment and Resources, Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute, Watanuki, Takasaki, Gunma, 370-1292 Japan
5. ISIS Muon division, Rutherford Appleton Laboratory (RAL), Chilton, Didcot, Oxon, UK OX11 0QX