[1] Univ Bari, Dipartmento Fis, Via Amendola 173, I-70126 Bari, Italy
[2] Ist Nazl Fis Nucl, I-70126 Bari, Italy
[3] Univ Bologna, Dipartimento Fis, I-40126 Bologna, Italy
[4] Ist Nazl Fis Nucl, I-40126 Bologna, Italy
[5] Boston Univ, Dept Phys, Boston, MA 02215 USA
[6] CALTECH, Pasadena, CA 91125 USA
[7] Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA
[8] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Rome, Italy
[9] Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, I-67010 Laquila, Italy
[10] Indiana Univ, Dept Phys, Bloomington, IN 47405 USA
[11] Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy
[12] Univ Lecce, Dipartimento Fis, I-73100 Lecce, Italy
[13] Ist Nazl Fis Nucl, I-73100 Lecce, Italy
[14] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA
[15] Univ Naples Federico II, Dipartimento Fis, I-80125 Naples, Italy
[16] Ist Nazl Fis Nucl, I-80125 Naples, Italy
[17] Ist Nazl Fis Nucl, I-56010 Pisa, Italy
[18] Univ Pisa, Dipartimento Fis, I-56010 Pisa, Italy
[19] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy
[20] Ist Nazl Fis Nucl, I-00185 Rome, Italy
[21] Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA
[22] Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, Italy
[23] Ist Nazl Fis Nucl, I-10125 Turin, Italy
[24] Univ Mohammed 1, Fac Sci, LPTP, Oujda, Morocco
[25] INFN Catania, I-95129 Catania, Italy
[26] Univ Basilicata, I-85100 Potenza, Italy
[27] INFN Milano, I-20133 Milan, Italy
[28] CNR, Ist TESRE, I-40129 Bologna, Italy
[29] Penn State Univ, Dept Phys, University Pk, PA 16802 USA
[30] Univ Roma Tre, Dipartimento Fis, Rome, Italy
[31] Univ Trieste, I-34100 Trieste, Italy
[32] Ist Nazl Fis Nucl, I-34100 Trieste, Italy
[33] Univ Rome, Dipartimento Energet, I-00185 Rome, Italy
[34] Swarthmore Coll, Swarthmore, PA 19081 USA
[35] PINSTECH, RPD, Islamabad, Pakistan
[36] Russian Acad Sci, Inst Nucl Res, RU-117312 Moscow, Russia
[37] Scuola Normale Super Pisa, I-56010 Pisa, Italy
[38] Inst Space Sci, Bucharest 76900, Romania
[39] Tektronix Inc, Wilsonville, OR 97070 USA