Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons
arXiv:1401.6284 · doi:10.1016/j.nuclphysb.2014.07.019
Abstract
Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS muon beam at $160$ GeV/c and a $^6$LiD target. The amplitudes of the three azimuthal modulations $\cosÏ_h$, $\cos2Ï_h$ and $\sinÏ_h$ were obtained binning the data separately in each of the relevant kinematic variables $x$, $z$ or $p_T^{\,h}$ and binning in a three-dimensional grid of these three variables. The amplitudes of the $\cos Ï_h$ and $\cos 2Ï_h$ modulations show strong kinematic dependencies both for positive and negative hadrons.
33 pages, 15 figures and 10 pages