Speaker
Description
This work presents a generalization of the asymmetric-frame approach to generalized parton distributions that explicitly includes longitudinal momentum transfer, enabling studies at nonzero skewness $\xi$. The method reorganizes nucleon matrix elements into Lorentz-invariant, frame-independent amplitudes -- an extension of our earlier $\xi=0$ work in unpolarized, helicity, and transversity sectors -- with a wide range of accessible kinematics in a single lattice calculation, which allows a mapping of GPDs from the lattice. We validate the general-$\xi$ formalism using two sets of momentum transfer: with combined transverse and longitudinal transfer and with purely longitudinal transfer, the latter reducing the number of independent amplitudes. From coordinate-space correlators, we determine the invariant amplitudes and construct the unpolarized GPDs $H$ and $E$; we then build quasi-distributions and perform matching to the light cone. The talk will also clarify the main hurdles specific to $\xi\neq0$.
