Structure of the nucleon at leading and subleading twist in the covariant parton model

The covariant parton model is generalized to describe quark correlators in a systematic way. Previous results are reproduced for the T-even leading-twist transverse momentum dependent parton distribution functions (TMDs), and for the first time all T-even twist-3 TMDs are evaluated in this model. We apply the approach to evaluate the fully unintegrated quark correlator which allows us to understand the model-specific relations between different TMDs. We verify the consistency of the approach, present numerical results and compare to available TMD parametrization.

Automated summary

The covariant parton model is expanded to systematically describe quark correlators, including all T-even twist-3 TMDs for the first time. The approach is used to evaluate fully unintegrated quark correlators, allowing for a better understanding of the model-specific relations between different TMDs. The consistency of the approach is verified through numerical results and comparison to available TMD parametrization.