2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/187161We show that the problem of Random Walk with boundary attractive potential may be mapped onto the free massive bosonic Quantum Field Theory with a line of defect. This mapping permits to recover the statistical properties of the Random Walks by using boundary $S$--matrix and Form Factor techniques.17 pages, Latex, 3 figures includedHigh Energy Physics - TheoryCondensed Mattertext