2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/185258We analyze the prospects at a muon collider for measuring chargino masses in the $μ^+μ^-\to \tildeχ^+\tildeχ^-$ process in the threshold region. We find that for the lighter chargino of a mass $100-200$ GeV, a measurement better than $50-300$ MeV should be possible with 50 fb$^{-1}$ integrated luminosity. The accuracy obtained here is better than with other techniques or at other facilities. The muon sneutrino mass, which enters through the $\tildeν_μ$ exchange diagram, can also be simultaneously measured to a few GeV if it is not too heavy.13 pages, 3 figuresHigh Energy Physics - Phenomenologytext