2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47148The canonical description of the straight-line string is given in the einbein field formalism. The system is quantized and Regge spectrum is reproduced. The covariant analogue of the Newton-Wigner coordinate is found, and peculiarities of the gauge fixing in τ-reparametrization group are discussed.9 pages, LaTeX2e, no figuresHigh Energy Physics - Phenomenologytext