Azimuthal asymmetries of charged hadrons produced by high-energy muons scattered off longitudinally polarised deuterons

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2010-11, Vol.70 (1-2), p.39-49
• Main Authors: Alekseev, M. G., Alexandrov, Yu, Amoroso, A., Austregesilo, A., Barth, J., Baum, G., Bertini, R., Bettinelli, M., Birsa, R., Bradamante, F., Bravar, A., Bressan, A., Bussa, M. P., Chaberny, D., Chiosso, M., Chung, S. U., Cicuttin, A., Dalla Torre, S., Das, S., Dasgupta, S. S., Dhara, L., Donskov, S. V., Efremov, A., Eversheim, P. D., Eyrich, W., Ferrero, A., Finger, M., Franco, C., Garfagnini, R., Gautheron, F., Giorgi, M., Gnesi, I., Grube, B., Gushterski, R., Haas, F., Hasegawa, T., Heß, C., Horikawa, N., Ilgner, C., Joosten, R., Kang, D., Khaustov, G. V., Kisselev, Yu, Klein, F., Koblitz, S., Kolosov, V. N., Konorov, I., Korzenev, A., Kouznetsov, O., Kral, A., Kurek, K., Lehmann, A., Liska, T., Magnon, A., Mann, A., Marchand, C., Martin, A., Massmann, F., Meyer, W., Mikhailov, Yu. V., Nerling, F., Neubert, S., Neyret, D., Nikolaenko, V. I., Olshevsky, A. G., Panknin, R., Perevalova, E., Pesaro, G., Platchkov, S., Rajotte, J.-F., Richter, A., Robinet, F., Rondio, E., Samoylenko, V. D., Sandacz, A., Santos, H., Sapozhnikov, M. G., Savin, I. A., Schmitt, L., Schopferer, S., Siebert, H.-W., Silva, L., Sinha, L., Smirnov, G. I., Sosio, S., Sozzi, F., Stolarski, M., Sulej, R., Takekawa, S., Uhl, S., Uman, I., Virius, M., Vossen, A., Weitzel, Q., Windmolders, R., Zaremba, K., Zavertyaev, M., Zemlyanichkina, E., Zhao, J., Zvyagin, A.
• Format: Article
• Language: English
• Subjects: Amplitudes; Astronomy; Astrophysics and Cosmology; Asymmetry; Dependence; Deuterons; Elementary Particles; Exact sciences and technology; Hadrons; Heavy Ions; Inelastic scattering; Longitude; Magnetic properties; Measurement Science and Instrumentation; Modulation; Muons; Nuclear Energy; Nuclear Experiment; Nuclear Physics; Partons; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Regular Article - Experimental Physics; String Theory; The physics of elementary particles and fields; Transverse momentum
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-010-1461-9

Azimuthal asymmetries in semi-inclusive production of positive ( h + ) and negative hadrons ( h − ) have been measured by scattering 160 GeV muons off longitudinally polarised deuterons at CERN. The asymmetries were decomposed in several terms according to their expected modulation in the azimuthal angle φ of the outgoing hadron. Each term receives contributions from one or several spin and transverse-momentum-dependent parton distribution and fragmentation functions. The amplitudes of all φ -modulation terms of the hadron asymmetries integrated over the kinematic variables are found to be consistent with zero within statistical errors, while the constant terms are nonzero and equal for h + and h − within the statistical errors. The dependencies of the φ -modulated terms versus the Bjorken momentum fraction x , the hadron fractional momentum z , and the hadron transverse momentum were studied. The x dependence of the constant terms for both positive and negative hadrons is in agreement with the longitudinal double-spin hadron asymmetries, measured in semi-inclusive deep-inelastic scattering. The x dependence of the sin  φ -modulation term is less pronounced than that in the corresponding HERMES data. All other dependencies of the φ -modulation amplitudes are consistent with zero within the statistical errors.