[1] UNIV BOLOGNA,DEPARTIMENTO FIS,I-40126 BOLOGNA,ITALY
[2] UNIV ROMA 2,IST NATL FIS NUCL,SEZ ROMA,GRP COLLEGATO ROMA 2,I-00173 ROME,ITALY
[3] IST NATL FIS NUCL,SEZ PISA,I-56100 PISA,ITALY
[4] UNIV ROMA 2,DIPARTIMENTO FIS,I-00173 ROME,ITALY
[5] UNIV CAGLIARI,DIPARTIMENTO FIS,I-91000 CAGLIARI,ITALY
[6] UNIV CAGLIARI,IST NATL FIS NUCL,SEZ CAGLIARI,I-91000 CAGLIARI,ITALY
[7] UNIV ROME LA SAPIENZA,IST NATL FIS NUCL,SEZ ROMA,I-00185 ROME,ITALY
[8] UNIV ROME LA SAPIENZA,DEPARTIMENTO FIS,I-00185 ROME,ITALY