Exclusive leptoproduction of p(0) mesons from hydrogen at intermediate virtual photon energies

Airapetian, A; Akopov, N; Akushevich, I; Amarian, M; Arrington, J; Aschenauer, Ec; Avakian, H; Avakian, R; Avetissian, A; Avetissian, E; Bailey, P; Bains, B; Baumgarten, C; Beckmann, M; Belostotski, S; Bernreuther, S; Bianchi, N; Bottcher, H; Borissov, A; Bouwhuis, M; Brack, J; Brauksiepe, S; Braun, B; Bruckner, W; Brull, A; Budz, P; Bulten, Hj; Capitani, Gp; Carter, P; Chumney, P; Cisbani, E; Court, Gr; Dalpiaz, Pf; DE LEO, Raffaele; De Nardo, L; De Sanctis, E; De Schepper, D; Devitsin, E; Pkad, Huberts; Di Nezza, P; Djordjadze, V; Duren, M; Dvoredsky, A; Elbakian, G; Ely, J; Fantoni, A; Fechtchenko, A; Ferro Luzzi, M; Fiedler, K; Filippone, Bw; Fischer, H; Fox, B; Franz, J; Frullani, S; Garber, Y; Garibaldi, F; Garutti, E; Gavrilov, G; Gharibyan, V; Golendukhin, A; Graw, G; Grebeniouk, O; Green, Pw; Greeniaus, Lg; Gute, A; Haeberli, W; Hartig, M; Hasch, D; Heesbeen, D; Heinsius, Fh; Henoch, M; Hertenberger, R; Wha, Hesselink; Hoffmann Rothe, P; Hofman, G; Holler, Y; Holt, Rj; Hommez, B; Hoprich, W; Iarygin, G; Ihssen, H; Iodice, M; Izotov, A; Jackson, He; Jgoun, A; Kaiser, R; Kanesaka, J; Kinney, E; Kisselev, A; Kitching, P; Kobayashi, H; Koch, N; Konigsmann, K; Kolstein, M; Kolster, H; Korotkov, V; Kotik, E; Kozlov, V; Krivokhijine, Vg; Kyle, G; Lagamba, L; Laziev, A; Lenisa, P; Lindemann, T; Lorenzon, W; Ncr, Makins; Martin, Jw; Marukyan, H; Masoli, F; Mcandrew, M; Mcilhany, K; Mckeown, Rd; Meissner, F; Menden, F; Metz, A; Meyners, N; Mikloukho, O; Miller, Ca; Milner, R; Mitsyn, V; Muccifora, V; Mussa, R; Nagaitsev, A; Nappi, E; Naryshkin, Y; Nass, A; Nowak, Wd; Apos, O; Neill, Tg; Openshaw, R; Ouyang, J; Owen, Br; Pate, Sf; Potashov, S; Potterveld, Dh; Rakness, G; Redwine, R; Reggiani, D; Reolon, Ar; Ristinen, R; Rith, K; Robinson, D; Ruh, M; Ryckbosch, D; Sakemi, Y; Sevin, I; Scarlett, C; Schill, C; Schmidt, F; Schmitt, M; Schnell, G; Schuler, Kp; Schwind, A; Seibert, J; Shibata, Ta; Shin, T; Shutov, V; Simani, C; Simon, A; Sinram, K; Steffens, E; Jjm, Steijger; Stewart, J; Stosslein, U; Suetsugu, K; Sutter, M; Tallini, H; Taroian, S; Terkulov, A; Tessarin, S; Thomas, E; Tipton, B; Tytgat, M; Urciuoli, Gm; van den Brand JFJ,; van der Steenhoven, G; van de Vyver, R; van Hunen JJ,; Vetterli, Mc; Vikhrov, V; Vincter, Mg; Visser, J; Volk, E; Weiskopf, C; Wendland, J; Wilbert, J; Wise, T; Woller, K; Yoneyama, S; Zohrabian, H.

doi:10.1007/s100520000483

Measurements of the cross section for exclusive virtual-photoproduction of rho (0) mesons from hydrogen are reported. The data were collected by the HERMES experiment using 27.5 GeV positrons incident on a hydrogen gas target in the HERA storage ring. The invariant mass W of the photon-nucleon system ranges from 4.0 to 6.0 GeV, while the negative squared four-momentum Q(2) Of the virtual photon varies from 0.7 to 5.0 GeV2. The present data together with roost of the previous data in the intermediate W-domain are well described by a model that infers the W-dependence of the cross section from the dependence on the Bjorken scaling variables of the unpolarized structure function for deep-inelastic scattering. In addition, a model calculation based on OR-Forward Parton Distributions gives a fairly good account of the longitudinal component of the rho (0) production cross section for Q(2) > 2 GeV2.