Spin asymmetries for events with high p(T) hadrons in DIS and an evaluation of the gluon polarization.

Adeva, B.; Arik, E.; Arvidson, A.; Badełek, B.; Baum, G.; Berglund, P.; Betev, L.; Birsa, R.; de Botton, N.; BRADAMANTE, FRANCO; Bravar, A.; BRESSAN, Andrea; Bueltmann, S.; Burtin, E.; Crabb, D.; Cranshaw, J.; Cuhadar, T.; DALLA TORRE, SILVIA; van Dantzig, R.; Derro, B.; Deshpande, A.; Dhawan, S.; Dulya, C.; Eichblatt, S.; Fasching, D.; Feinstein, F.; Fernandez, C.; Frois, B.; Gallas, A.; Garzon, J. A.; Gilly, H.; GIORGI, MARCELLO; von Goeler, E.; Goertz, S.; Gracia, G.; de Groot, N.; Grosse Perdekamp, M.; Haft, K.; von Harrach, D.; Hasegawa, T.; Hautle, i. P.; Hayashi, j. N.; Heusch, k. C. A.; Horikawa, l. N.; Hughes, V. W.; Igo, G.; Ishimoto, S.; Iwata, T.; Kabuß, E. M.; Karev, A.; Kessler, H. J.; Ketel, T. J.; Kiryluk, J.; Kisselev, Y.; Klostermann, L.; Kowalik, K.; Kotzinian, A.; Kroeger, W.; Kunne, F.; Kurek, K.; Kyynarainen, J.; LAMANNA, MASSIMO; Landgraf, U.; Le Goff, J. M.; Lehar, F.; de Lesquen, A.; Lichtenstadt, J.; Litmaath, M.; Magnon, A.; Mallot, G. K.; Marie, F.; MARTIN, ANNA; Martino, J.; Matsuda, T.; Mayes, B.; Mccarthy, J. S.; Medved, K.; Meyer, W.; Miller, D.; Miyachi, Y.; Mori, K.; Moromisato, J.; Nassalski, J.; Niinikoski, T. O.; Oberski, J. E. J.; Ogawa, A.; Ozben, C.; Pereira, H.; Peshekhonov, D.; Piegaia, R.; Pinsky, L.; Platchkov, S.; Plo, M.; Pose, D.; Postma, H.; Pretz, J.; Radel, G.; Reicherz, G.; Roberts, J.; Rodriguez, M.; Rondio, E.; Sabo, I.; Saborido, J.; Sandacz, A.; Savin, I.; SCHIAVON, PAOLO; Sichtermann, E. P.; Simeoni, F.; Smirnov, G. I.; Staude, A.; Steinmetz, A.; Stiegler, U.; Stuhrmann, H.; Sulej, R.; TESSAROTTO, FULVIO; Thers, D.; Tłaczała, W.; Tripet, A.; Unel, G.; Velasco, M.; Vogt, J.; Voss, R.; Whitten, C.; Windmolders, R.; Willumeit, R.; Wislicki, W.; Witzmann, A.; Zanetti, A. M.; Zaremba, K.; Zhao, J.

Spin asymmetries for events with high p(T) hadrons in DIS and an evaluation of the gluon polarization.

Adeva, B.

•

Arik, E.

•

Arvidson, A.

altro

Zhao, J.

2004

journal article

Periodico

PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY

Abstract

We present a measurement of the longitudinal spin cross section asymmetry for deep-inelastic muon-nucleon interactions with two high transverse momentum hadrons in the final state. Two methods of event classification are used to increase the contribution of the photon-gluon fusion process to above 30%. The most effective one, based on a neural network approach, provides the asymmetries A(p)lN(-->)lhhX=0.030+/-0.057(stat)+/-0.010(syst) and A(d)lN(-->)lhhX=0.070+/-0.076(stat)+/-0.010(syst). From these values we derive an averaged gluon polarization DeltaG/G=-0.20+/-0.28(stat)+/-0.10(syst) at an average fraction of nucleon momentum carried by gluons <eta>=0.07