Affiliation: | a Institut für Kernphysik, Forschungszentrum Karlsruhe, 76021 Karlsruhe, Germany b National Institute of Physics and Nuclear Engineering, 7690 Bucharest, Romania c Cosmic Ray Division, Yerevan Physics Institute, Yerevan 36, Armenia d Institut für Experimentelle Kernphysik, University of Karlsruhe, 76021 Karlsruhe, Germany e Department of Experimental Physics, University of Lodz, 90236 Lodz, Poland f Soltan Institute for Nuclear Studies, 90950 Lodz, Poland |