2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/203151We discuss a rigid string model proposed by Casalbuoni and Longhi. Constraints for the massive states are solved to find the physical states and the mass spectrum. We also find its supersymmetric extension with the kappa symmetry. The supersymmetry transformations are found starting from on-shell transformations using the Dirac bracket.16 pages with no fugure, references addedHigh Energy Physics - Theorytext