Towards a model independent extraction of the Boer-Mulders function

Abstract

At present, the Boer-Mulders function for a given quark flavour has been extracted from data on semi-inclusive deep inelastic scattering using the simplifying, but theoretically inconsistent, assumption that it is proportional to the Sivers function for each quark flavour. In this paper, using the latest semi-inclusive deep inelastic COMPASS deuteron data on the $⟨\cos \ddot{I}{•}_h⟩$ and $⟨\cos 2\ddot{I}{•}_h⟩$ asymmetries we extract the collinear $x_B$-dependence of the Boer-Mulders function for the sum of the valence quarks $Q_V=u_V+d_V$ in an essentially model independent way, and find a significant disagreement with the published results. Our analysis also yields interesting information on the transverse momentum dependence of the unpolarized quark distribution and fragmentation functions.

6 pages, 4 figures