1. Lab. of Physics, Osaka Electro-Communication University, Neyagawa 572-8530, Japan
2. Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000, U.S.A.
3. Nuclear Physics Institute, 250 68 Řež near Prague, Czech Republic
4. Miyazaki Medical College, Miyazaki 889-1692, Japan
5. Department of Physics, Chiba University, Chiba 263-8522, Japan
6. Department of Physics, Tohoku University, Sendai 980-8578, Japan