Evidence for the onset of color transparency in rho(0) electroproduction off nuclei

Fassi, L. E.; Zana, L.; Hafidi, K.; Holtrop, M.; Mustapha, B.; Brooks, W. K.; Hakobyan, H.; Zheng, X.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amaryan, M. J.; Anghinolfi, M.; Arrington, J.; Avakian, H.; Baghdasaryan, H.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Bookwalter, C.; Branford, D.; Briscoe, W. J.; Bueltmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, Marco; Crede, V.; D'Angelo, A.; Daniel, A.; Dashyan, N.; Vita, R. D.; Sanctis, E. D.; Deur, A.; Dey, B.; Dickson, R.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dupre, R.; Egiyan, H.; Alaoui, A. E.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Gabrielyan, M. Y.; Garcon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hanretty, C.; Heddle, D.; Hicks, K.; Holt, R. J.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jawalkar, S. S.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Kuznetsov, V.; Laget, J. M.; H. Y., Lu; I. J. D.,; Mao, Y.; Markov, N.; Mayer, M.; Mcandrew, J.; Mckinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moreno, B.; Moutarde, H.; Munevar, E.; Nadel Turonski, P.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenkov, M.; Ostrovidov, A. I.; Pappalardo, Luciano Libero; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Pereira, S. A.; Phelps, E.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Raue, B. A.; Reimer, P. E.; Ricco, G.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatie, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tedeschi, D. J.; Tkachenko, S.; Ungaro, M.; Vernarsky, B.; Vineyard, M. F.; Voskanyan, H.; Voutier, E.; Watts, D.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zachariou, N.; Zhao, B.; Zhao, Z. W.

doi:10.1016/j.physletb.2012.05.019

We have measured the nuclear transparency of the incoherent diffractive A(e,eρ0) process in 12 Cand 56Fe targets relative to 2H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced ρ0’s on a nucleus relative to deuterium, which is sensitive to ρA interaction, was studied as function of the coherence length (lc), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared (Q2). While the transparency for both 12 Cand56Fe showed no lc dependence, a significant Q2 dependence was measured, which is consistent with calculations that included the color transparency effects.