[1] Univ Pavia, Dipartmento Fis, Ist Nazl Fis Nucl, Sez Pavia, I-27100 Pavia, Italy
[2] Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, Assergi, Laquila, Italy
[3] Warsaw Univ, Inst Expt Phys, Warsaw, Poland
[4] ETH Honggerberg, Inst Particle Phys, CH-8093 Zurich, Switzerland
[5] Univ Padua, Dipartimento Fis, Padua, Italy
[6] Ist Nazl Fis Nucl, Padua, Italy
[7] Silesian Univ, Inst Phys, PL-40007 Katowice, Poland
[8] Univ Granada, Dept Fis Teor & Cosmos, Granada, Spain
[9] Univ Granada, CAFPE, Granada, Spain
[10] Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy
[11] Univ Aquila, Ist Nazl Fis Nucl, I-67100 Laquila, Italy
[12] CERN, CH-1211 Geneva, Switzerland
[13] Univ Milan, Politecn Milan, CESNEF, Milan, Italy
[14] IHEP, Acad Sinica, Beijing, Peoples R China
[15] Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA
[16] H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland
[17] Univ Wroclaw, Inst Theoret Phys, PL-50138 Wroclaw, Poland
[18] Soltan Inst Nucl Studies, PL-00681 Warsaw, Poland
[19] Krakow Tech Univ, Inst Mech & Machine Design, PL-31155 Krakow, Poland
[20] Stanislaw Staszic Univ Min & Met, PL-30059 Krakow, Poland
[21] IFSI Torino, Turin, Italy
[22] Univ Turin, Dipartimento Fis, Turin, Italy
[23] Ist Nazl Fis Nucl, Lab Nazl Frascati, Frascati, Roma, Italy
[24] Ist Nazl Fis Nucl, Pisa, Italy
[25] Jagiellonian Univ, Inst Phys, Krakow, Poland