Speaker
Description
Potential experimental signatures of generalized transverse momentum-dependent distributions (GTMDs) are proposed through exclusive pseudoscalar and heavy (axial-)vector meson production in lepton-proton collisions. Within the framework of collinear twist-3 factorization, we show that specific azimuthal-angle-dependent observables are sensitive to the quark and gluon GTMDs $F_{1,4}$ and $G_{1,1}$, which are directly connected to partonic orbital angular momentum and spin-orbit correlations, respectively. These distributions probe a unique sector of nucleon structure and have no counterparts within the generalized parton distribution or transverse-momentum-dependent frameworks. We point out that sin2ϕ and cos2ϕ modulations provide clear experimental signatures of these otherwise elusive GTMDs, thereby opening a new avenue for accessing the spin structure of the nucleon.