2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/56084Quantization of 4-dimensional Nambu-Goto theory of open string in light cone gauge, related in Lorentz-invariant way with the world sheet, is performed. Obtained quantum theory has no anomalies in Lorentz group. Determined spin-mass spectra of the theory have Regge-like behavior and do not contain the tachyon. Vertex operators of interaction theory, acting in the physical subspace, are constructed.15 pages, 9 figures, 3 tables; talk at Int. School of Subnuclear Physics, Aug 29 - Sept 7 1998, Erice (Sicily); submitted to Int.J.Mod.Phys.AHigh Energy Physics - Theorytext