2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44640We map the parameter space that leads to stable Z-vortices in the electroweak model. For $sin^2 θ_W = 0.23$, we find that the strings are unstable for a Higgs mass larger than 24 GeV. Given the latest constraints on the Higgs mass from LEP, this shows that, if the standard electroweak model is realized in Nature, the Z-vortex (in the bare model) is unstable.1 figure (not include d, available upon request). Use jnl and reforder macrosHigh Energy Physics - PhenomenologyOn the Stability of Electroweak Strings (New Version)text