Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons
C. Adolph (Universität Erlangen–Nürnberg, Physikalisches Institut, Erlangen, 91054, Germany); R. Akhunzyanov (Joint Institute for Nuclear Research, Dubna, Moscow Region, 141980, Russia); M.G. Alexeev (Torino Section of INFN, Turin, 10125, Italy); Yu. Alexandrov (Lebedev Physical Institute, Moscow, 119991, Russia); G.D. Alexeev (Joint Institute for Nuclear Research, Dubna, Moscow Region, 141980, Russia); et al - Show all 221 authors
Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS longitudinally polarised muon beam at 160 GeV/c and a 6 LiD target. The amplitudes of the three azimuthal modulations cosâ¡Ïh , cosâ¡2Ïh and sinâ¡Ïh were obtained binning the data separately in each of the relevant kinematic variables x , z or pTh and binning in a three-dimensional grid of these three variables. The amplitudes of the cosâ¡Ïh and cosâ¡2Ïh modulations show strong kinematic dependencies both for positive and negative hadrons.