Flavor decomposition of the sea-quark helicity distributions in the nucleon from semiinclusive deep inelastic scattering.

/ Authors

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

and 169 more authors

E. Avetissian, P. Bailey, V. Baturin, C. Baumgarten, M. Beckmann, S. Belostotski, S. Bernreuther, N. Bianchi, H. Blok, H. Böttcher, A. Borissov, M. Bouwhuis, J. Brack, A. Brüll, V. Bryzgalov, G. Capitani, H. Chiang, G. Ciullo, M. Contalbrigo, P. Dalpiaz, R. De Leo, L. De Nardo, E. De Sanctis, E. Devitsin, P. Di Nezza, M. Düren, M. Ehrenfried, A. Elalaoui-Moulay, G. Elbakian, F. Ellinghaus, U. Elschenbroich, J. Ely, R. Fabbri, A. Fantoni, A. Fechtchenko, L. Felawka, B. Fox, J. Franz, S. Frullani, Y. Gärber, G. Gapienko, V. Gapienko, F. Garibaldi, K. Garrow, E. Garutti, D. Gaskell, G. Gavrilov, V. Gharibyan, G. Graw, O. Grebeniouk, L. G. Greeniaus, K. Hafidi, M. Hartig, D. Hasch, D. Heesbeen, M. Henoch, R. Hertenberger, W. Hesselink, A. Hillenbrand, M. Hoek, Y. Holler, B. Hommez, G. Iarygin, A. Ivanilov, A. Izotov, H. Jackson, A. Jgoun, R. Kaiser, E. Kinney, A. Kisselev, K. Königsmann, M. Kopytin, V. Korotkov, V. Kozlov, B. Krauss, V. Krivokhijine, L. Lagamba, L. Lapiḱas, A. Laziev, P. Lenisa, P. Liebing, T. Lindemann, K. Lipka, W. Lorenzon, J. Lu, B. Maiheu, N. Makins, B. Mariański, H. Marukyan, F. Masoli, V. Mexner, N. Meyners, O. Mikloukho, C. A. Miller, Y. Miyachi, V. Muccifora, A. Nagaitsev, E. Nappi, Y. Naryshkin, A. Nass, M. Negodaev, W. Nowak, K. Oganessyan, H. Ohsuga, G. Orlandi, N. Pickert, S. Potashov, D. Potterveld, M. Raithel, D. Reggiani, P. Reimer, A. Reischl, A. Reolon, C. Riedl, K. Rith, G. Rosner, A. Rostomyan, L. Rubacek, D. Ryckbosch, Y. Salomatin, I. Sanjiev, I. Savin, C. Scarlett, A. Schäfer, C. Schill, G. Schnell, K. Schüler, A. Schwind, J. Seele, R. Seidl, B. Seitz, R. Shanidze, C. Shearer, T. Shibata, V. Shutov, M. C. Simani, K. Sinram, M. Stancari, M. Statera, E. Steffens, J. Steijger, J. Stewart, U. Stösslein, P. Tait, H. Tanaka, S. Taroian, B. Tchuiko, A. Terkulov, A. Tkabladze, A. Trzciński, M. Tytgat, A. Vandenbroucke, P. B. van der Nat, G. van der Steenhoven, M. Vetterli, V. Vikhrov, M. Vincter, J. Visser, C. Vogel, M. Vogt, J. Volmer, C. Weiskopf, J. Wendland, J. Wilbert, G. Y. Ybeles Smit, S. Yen, B. Zihlmann, H. Zohrabian, P. Żupránski

/ Abstract

Double-spin asymmetries of semiinclusive cross sections for the production of identified pions and kaons have been measured in deep inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with reanalyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.

Journal: Physical review letters

DOI: 10.1103/PhysRevLett.92.012005