Affiliation: | aHigh Energy Accelerator Research Organization (KEK), 1-1Oho, Tsukuba 305-0801, Japan bInstitute for Theoretical Solid-State Physics, University of Karlsruhe, D-76128 Karlsruhe, Germany cDepartment of Accelerator and Medical Physics, National Institute of Radiological Sciences, Anagawa, Chiba 263-8555, Japan dFaculty of Human Environment, Kyoto Prefectural University, Kyoto 606-8522, Japan |