Evidence for quark-hadron duality in the proton spin asymmetry A1.

/ Authors

A. Airapetian, N. Akopov, Z. Akopov, M. Amarian, V. Ammosov, E. Aschenauer, H. Avakian, R. Avakian, A. Avetissian, E. Avetissian

and 168 more authors

P. Bailey, V. Baturin, C. Baumgarten, M. Beckmann, S. Belostotski, S. Bernreuther, N. Bianchi, H. Blok, H. Böttcher, A. Borissov, O. Bouhali, M. Bouwhuis, J. Brack, S. Brauksiepe, A. Brüll, I. Brunn, H. Bulten, G. Capitani, E. Cisbani, G. Ciullo, G. Court, P. Dalpiaz, R. De Leo, L. De Nardo, E. De Sanctis, E. Devitsin, P. D. W. de Witt Huberts, P. Di Nezza, M. Düren, M. Ehrenfried, G. Elbakian, F. Ellinghaus, U. Elschenbroich, J. Ely, R. Fabbri, A. Fantoni, A. Fechtchenko, L. Felawka, B. Filippone, H. Fischer, B. Fox, J. Franz, S. Frullani, Y. Gärber, V. Gapienko, F. Garibaldi, E. Garutti, G. Gavrilov, V. Gharibyan, G. Graw, O. Grebeniouk, P. Green, L. G. Greeniaus, A. Gute, W. Haeberli, K. Hafidi, M. Hartig, D. Hasch, D. Heesbeen, F. Heinsius, M. Henoch, R. Hertenberger, W. Hesselink, G. Hofman, Y. Holler, R. Holt, B. Hommez, G. Iarygin, A. Izotov, H. Jackson, A. Jgoun, P. Jung, R. Kaiser, E. Kinney, A. Kisselev, P. Kitching, K. Königsmann, H. Kolster, M. Kopytin, V. Korotkov, É. Kotik, V. Kozlov, B. Krauss, V. Krivokhijine, G. Kyle, L. Lagamba, A. Laziev, P. Lenisa, P. Liebing, T. Lindemann, W. Lorenzon, A. Maas, N. Makins, H. Marukyan, F. Masoli, F. Menden, V. Mexner, N. Meyners, O. Mikloukho, C. A. Miller, V. Muccifora, A. Nagaitsev, E. Nappi, Y. Naryshkin, A. Nass, K. Negodaeva, W. Nowak, K. Oganessyan, G. Orlandi, S. Podiatchev, S. Potashov, D. Potterveld, M. Raithel, V. Rappoport, D. Reggiani, P. Reimer, A. Reischl, A. Reolon, K. Rith, A. Rostomyan, D. Ryckbosch, Y. Sakemi, I. Sanjiev, F. Sato, I. Savin, C. Scarlett, A. Schäfer, C. Schill, F. Schmidt, G. Schnell, K. Schüler, A. Schwind, J. Seibert, B. Seitz, R. Shanidze, T. Shibata, V. Shutov, M. C. Simani, K. Sinram, M. Stancari, E. Steffens, J. Steijger, J. Stewart, U. Stösslein, K. Suetsugu, S. Taroian, A. Terkulov, S. Tessarin, E. Thomas, B. Tipton, M. Tytgat, G. Urciuoli, J. V. D. van den Brand, G. van der Steenhoven, R. van de Vyver, M. Vetterli, V. Vikhrov, M. Vincter, J. Visser, J. Volmer, C. Weiskopf, J. Wendland, J. Wilbert, T. Wise, S. Yen, S. Yoneyama, B. Zihlmann, H. Zohrabian

/ Abstract

Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1. Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q2 between 1.2 and 12 GeV2 and values of W2 between 1 and 4 GeV2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable x. This finding implies that the description of A1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q2 above 1.6 GeV2.

Journal: Physical review letters

DOI: 10.1103/PhysRevLett.90.092002