2024/08/05 by Bockisch, Daniel
#FOS: Physical sciences #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2408.02609
We transform the one-loop four-point type I open superstring gluon amplitude to correlation functions on the celestial sphere including both the (non-)orientable planar and non-planar sector. This requires a Mellin transform with respect to the energies of the scattered strings, as well as to integrate over the open-string worldsheet moduli space. After accomplishing the former we obtain celestial string integrands with remaining worldsheet integrals Ψ(β), where β is related to the conformal scaling dimensions of the conformal primary operators under consideration. Employing an alternative approach of performing an α'-expansion of the open superstring amplitude first and Mellin transforming afterwards, we obtain a fully integrated expression, capturing the pole structure in the β-plane. The same analysis is performed at tree-level yielding similar results. We conclude by solving Ψ(β) for specific values of β, consistently reproducing the results of the α'-expansion ansatz. In all approaches we find that the dependence on α' reduces to that of a simple overall factor of (α')β-3 at loop and (α')β at tree level, consistent with previous literature.