[1] Univ Paris 11, CNRS, IN2P3, LAL, F-91898 Orsay, France
[2] Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy
[3] Univ Perugia, I-06123 Perugia, Italy
[4] Univ Salerno, I-84084 Salerno, Italy
[5] Univ Naples Federico II, I-80126 Naples, Italy
[6] Ist Nazl Fis Nucl, Sez Napoli, Naples, Italy
[7] Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy
[8] EGO, I-56021 Cascina, PI, Italy
[9] Univ Pisa, I-56127 Pisa, Italy
[10] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy
[11] Lab Annecy Le Vieux Phys Particules, F-74941 Annecy Le Vieux, France
[12] ESPCI, F-75005 Paris, France
[13] Observ Cote Azur, Dept Fresnel Interferometrie Laser Gravitat & Ast, F-06304 Nice 4, France
[14] Ist Nazl Fis Nucl, Sez Firenzel Urbino, I-50019 Sesto Fiorentino, Italy
[15] Univ Florence, I-50125 Florence, Italy
[16] Osserv Astrofis Arcetri, I-50125 Florence, Italy
[17] Univ Urbino, I-61029 Urbino, Italy
[18] Ist Nazl Fis Nucl, Sez Roma, I-00185 Rome, Italy
[19] Univ Roma La Sapienza, I-00185 Rome, Italy
[20] SMA, IPNL 22, F-69622 Villeurbanne, France