  Previous Lattice QCD calculations of nucleon transverse momentum-dependent
parton distributions (TMDs) focused on the case of transversely polarized
nucleons, and thus did not encompass two leading-twist TMDs associated with
longitudinal polarization, namely, the helicity TMD and the worm-gear TMD
corresponding to transversely polarized quarks in a longitudinally polarized
nucleon. Based on a definition of TMDs via hadronic matrix elements of quark
bilocal operators containing staple-shaped gauge connections, TMD observables
characterizing the aforementioned two TMDs are evaluated, utilizing an
RBC/UKQCD domain wall fermion ensemble at the physical pion mass.
