[1] Univ Lecce, Dipartimento Fis, I-73100 Lecce, Italy
[2] Ist Nazl Fis Nucl, I-73100 Lecce, Italy
[3] Univ Naples, Dipartimento Fis, I-80125 Naples, Italy
[4] Ist Nazl Fis Nucl, I-80125 Naples, Italy
[5] Ist Nazl Fis Nucl, Lab Nazl Gran Sasso, I-67010 Assergi, Aquila, Italy
[6] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy
[7] Ist Nazl Fis Nucl, I-00185 Rome, Italy
[8] Univ Bologna, Dipartimento Fis, I-40126 Bologna, Italy
[9] Ist Nazl Fis Nucl, I-40126 Bologna, Italy
[10] Univ Mohamed I, Fac Sci, LPTP, Oujda, Morocco
[11] Univ Pisa, Dipartimento Fis, I-56010 Pisa, Italy
[12] Ist Nazl Fis Nucl, I-56010 Pisa, Italy
[13] CALTECH, Pasadena, CA 91125 USA
[14] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Roma, Italy
[15] Univ Bari, Dipartimento Fis, I-70126 Bari, Italy
[16] Ist Nazl Fis Nucl, I-70126 Bari, Italy
[17] Indiana Univ, Dept Phys & Astron, Bloomington, IN 47405 USA
[18] Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy
[19] Ist Nazl Fis Nucl, Sez Roma Tre, I-00146 Rome, Italy
[20] Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy
[21] Ist Nazl Fis Nucl, I-67100 Laquila, Italy
[22] Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA
[23] Boston Univ, Dept Phys, Boston, MA 02215 USA
[24] Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA
[25] Univ Turin, Dipartimento Fis Sperimentale, I-10125 Turin, Italy
[26] Ist Nazl Fis Nucl, I-10125 Turin, Italy
[27] Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA
[28] Univ Basilicata, I-85100 Potenza, Italy
[29] Ist Nazl Fis Nucl, I-20133 Milan, Italy
[30] CNR, Ist TESRE, I-40129 Bologna, Italy
[31] Penn State Univ, Dept Phys, University Pk, PA 16801 USA
[32] Univ Trieste, I-34100 Trieste, Italy
[33] Ist Nazl Fis Nucl, I-34100 Trieste, Italy
[34] Univ Minnesota, Dept Phys, Duluth, MN 55812 USA
[35] Univ Rome, Dipartimento Energet, I-00185 Rome, Italy
[36] MIT, Dept Phys, Cambridge, MA 02139 USA
[37] Intervideo Inc, Torrance, CA 90505 USA
[38] Univ Calabria, Dipartimento Fis, I-87036 Arcavacata Di Rende, Cosenza, Italy
[39] PINSTECH, RPD, Islamabad, Pakistan
[40] Inst Space Sci, Bucharest 76900, Romania