Leading contribution of light double-twist operators at noninteger twist parameter

Determine whether the contribution of light double-twist operators remains leading in the parameter \(\mu\) when \(N=\Delta_L-d/2\) is not a nonnegative integer.

Background

The paper analyzes the heavy limit of the graviton-exchange Mellin amplitude. When $N=\Delta_L-d/2$ is a nonnegative integer, the stress-tensor descendant sum terminates, and the coefficients of light double-twist operators are shown to cancel the relevant stress-tensor descendant contributions up to corrections suppressed by powers of $\Delta_H$. For noninteger $N$, the truncation does not occur, and the authors explicitly leave unresolved whether the light double-twist contribution continues to appear at leading order in $\mu$.