[1] UNIV TRIESTE, DIPARTMENTO FIS, I-34127 TRIESTE, ITALY
[2] UNIV TRIESTE, SEZ INFN, I-34127 TRIESTE, ITALY
[3] UNIV ROMA TOR VERGATA, DIPARTIMENTO FIS, I-00173 ROME, ITALY
[4] UNIV ROMA TOR VERGATA, SEZ INFN, I-00173 ROME, ITALY
[5] UNIV FLORENCE, DIPARTMENTO FIS, FLORENCE, ITALY
[6] UNIV FLORENCE, SEZ INFN, FLORENCE, ITALY
[7] IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY
[8] UNIV BARI, DIPARTIMENTO FIS, BARI, ITALY
[9] UNIV BARI, SEZ INFN, BARI, ITALY
[10] UNIV PERUGIA, SEZ INFN, PERUGIA, ITALY
[11] UNIV PERUGIA, DIPARTIMENTO FIS, PERUGIA, ITALY
[12] UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY
[13] UNIV ROMA LA SAPIENZA, SEZ INFN, I-00185 ROME, ITALY
[14] NEW MEXICO STATE UNIV, LAS CRUCES, NM 88003 USA
[15] TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA
[16] NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA
[17] UNIV SIEGEN, W-5900 SIEGEN, GERMANY