A Direct Reconstruction of the Gaugino Parameters with Phases

A simple algebraic algorithm is described to recover the (complex valued) gaugino/Higgsino basic parameters $\mu = |\mu| e^{i \phi_\mu}$, $M_1 = |M_1| e^{i \phi_{M_1}}$, $M_2 = |M_2|$, directly in terms of (a minimal set of) neutralino and chargino masses, accurately measurable at future linear collider energies. An ambiguity in the $M_1$ reconstruction can be resolved by measuring the corresponding $e^+e^- \to \chi^0_1 \chi^0_2$ cross section. This approach should simplify the determination of allowed ranges of the gaugino parameters, in particular if only a partial set of gaugino masses were measured.