2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50679We study XXX Heisenberg spin 1/2 anti-ferromagnet. We evaluate a probability of formation of a ferromagnetic string in the anti-ferromagnetic ground state in thermodynamics limit. We prove that for short strings the probability can be expressed in terms of Riemann zeta function with odd arguments.High Energy Physics - TheoryStatistical MechanicsMathematical PhysicsNumber Theorytext