Flavor dependence of unpolarized TMDs from semi-inclusive pion production

Understand

Recent data from semi-inclusive deep inelastic scattering collected by the HERMES collaboration allow for the first time to discuss how the transverse-momentum dependence of unpolarized distribution and fragmentation functions is affected by the flavor of the involved partons.

• A model built with flavor-dependent Gaussian transverse-momentum distributions fits data better than the same flavor-independent model.
• The current analysis is performed for totally unpolarized scattering of leptons off protons and deuterons, with detected pions in the final state.
• There are convincing indications of flavor dependence in the fragmentation functions, while for parton distribution functions the evidence is weaker.