Abstract
We measured the longitudinal double spin asymmetries A(LL) for single hadron muoproduction off protons and deuterons at photon virtuality Q (2) < 1 (GeV/c)(2) for transverse hadron momenta p(T) in the range 1 GeV/c to 4 GeV/c. They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/c or 200 GeV/c impinging on polarised (LiD)-Li-6 or NH3 targets.
The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation Lambda G inside the nucleon in the range of the nucleon momentum fraction carried by gluons 0.05 < x(g) < 0.2. (C) 2015 The Authors. Published by Elsevier B.V.
This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).