Azimuthal asymmetries in unpolarized Drell-Yan processes and the Boer-Mulders distributions of antiquarks

Understand

Using a previous extraction of the quark Boer-Mulders distributions from semiinclusive deep inelastic scattering data, we fit the unpolarized Drell-Yan data on the $\cos 2 \phi$ asymmetry, determining the antiquark Boer-Mulders distributions.

• A good agreement with the data is found in the region of low $q_T$, where the transverse-momentum factorization approach applies.