2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/150654The scale in the D-brane theory is discussed from different points of view. It is shown that scattering of a $D_4$-brane by a $D_0$-brane gives the condition to penetrate beyond the string scale.Tex, 9 pages, No figures, we have some changes in the textHigh Energy Physics - Theorytext