Dilaton-dilatino superstring theory scattering amplitude and its Regge behavior
Lucas Martin, Martin Parlanti, Martin Schvellinger
TL;DR
The paper computes the tree-level scattering amplitude for two dilatons and two dilatinos in type II superstring theory using KLT relations, expressing the closed-string amplitude as products of open-string bosonic and fermionic kinematic factors. It performs a complete 270-term calculation and recovers a compact closed-string kinematic factor that exhibits $\tilde{s}$-$\tilde{u}$ duality, then analyzes the Regge limit to reveal the graviton Reggeization with trajectory $J(\tilde{t})=2+\frac{\alpha'\tilde{t}}{2}$. The full amplitude includes a product of Gamma-function factors $\prod_{\chi=\tilde{s},\tilde{t},\tilde{u}} \frac{\Gamma(-\alpha'\chi/4)}{\Gamma(1-\alpha'\chi/4)}$, and in the Regge regime it scales as a power of $\alpha'\tilde{s}$ consistent with graviton exchange. The results have implications for gauge/string duality and could inform hard scattering processes involving glueballs and fermions in the dual gauge theory.
Abstract
The tree-level type II superstring theory scattering amplitude of two dilatons and two dilatinos is explicitly calculated from the Kawai-Lewellen-Tye relations. The corresponding Regge behavior is obtained.