1. Joint Institute for Nuclear Research, 141980 Dubna, Russia
2. Institute für Kernphysik, Darmstadt University of Technology, 64289 Darmstadt, Germany
3. H. Niewodniczański Institute of Nuclear Physics, 31-342, Cracow, Poland
4. University of Iowa, Iowa City, IA 52242, USA
5. Institute for Nuclear Research, 117312 Moscow, Russia