Azimuthal distributions of charged hadrons, pions, and kaons produced in deep-inelastic scattering off unpolarized protons and deuterons

A. Airapetian, N. Akopov, Z. Akopov, E. C. Aschenauer, W. Augustyniak, R. Avakian, A. Avetissian, E. Avetisyan, S. Belostotski, H. P. Blok, A. Borissov, J. Bowles (+115 others)
2013 Physical Review D  
The azimuthal cosϕ and cos2ϕ modulations of the distribution of hadrons produced in unpolarized semi-inclusive deep-inelastic scattering of electrons and positrons off hydrogen and deuterium targets have been measured in the HERMES experiment. For the first time these modulations were determined in a four-dimensional kinematic space for positively and negatively charged pions and kaons separately, as well as for unidentified hadrons. These azimuthal dependences are sensitive to the transverse
more » ... tion and polarization of the quarks within the nucleon via, e.g., the Cahn, Boer-Mulders and Collins effects.
doi:10.1103/physrevd.87.012010 fatcat:ywolw7q7fjaydiwrkhmxklk5pe