Microscopic origin of additional Regge trajectories at nonzero cusp angle

Identify and characterize the precise microscopic Wilson‑line cusp operator insertions responsible for the additional Regge trajectories that appear at nonzero cusp angle \phi \neq 0 in Coulomb‑branch scattering of planar N=4 SYM, beyond the parity‑even SO(2)×SO(5) singlet insertions; determine their quantum numbers and dynamical role.

Background

Extending the Regge/cusp correspondence beyond the first two trajectories suggests the presence of additional (spinning) trajectories that decouple in the forward limit but appear for nonzero cusp angle.

While the authors argue these likely arise from spinning operator insertions at the cusp, current amplitude data do not allow a definitive microscopic identification; resolving this would complete the operator–trajectory dictionary.