2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/221396We study the production cross section of a highly excited string with fixed angular momentum from an ultra-high energy collision of two light strings. We find that the cross section exhibits geometric behavior in a certain region of angular-momentum/impact-parameter space. This geometric behavior is common to the differential cross sections of a black hole production with fixed angular momentum and thus we see another correspondence between strings and black holes.21 pages, 2 figures (v1); comments, references, and Appendix D added (v2)High Energy Physics - TheoryGeneral Relativity and Quantum CosmologyHigh Energy Physics - PhenomenologyGeometric cross sections of rotating strings and black holestext