2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/197792We apply the Sklyanin method of separation of variables to the reflection algebra underlying the open spin-1/2 XXX chain with non-diagonal boundary fields. The spectral problem can be formulated in terms of a TQ-equation which leads to the known Bethe equations for boundary parameters satisfying a constraint. For generic boundary parameters we study the asymptotic behaviour of the solutions of the TQ-equation.19 pages, references added; to appear in Nucl. Phys. BHigh Energy Physics - TheoryOther Condensed MatterMathematical Physicstext