Phases in the gaugino sector: Direct reconstruction of the basic parameters and the impact on neutralino pair production - art. no. 095003

We consider recovering analytically the (generally complex) parameters mu, M-1, and M-2 of the gaugino and Higgsino Lagrangian from appropriate physic al input in the chargino and neutralino sectors. For a given tan beta, we o btain very simple analytic solutions for M-2, \mu\ Arg[mu] in the chargino sector and a twofold \M-1\, Arg[M-1] analytic solution in the neutralino se ctor, assuming two chargino, two neutralino masses, and one of the chargino mixing angles as physical input. The twofold ambiguity in the neutralino p arameters reconstruction may be essentially resolved by measuring the e(+)e (-)-->chi(1)(o)chi(2)(o) production cross section at future linear collider energies, which we study explicitly with the phase dependences. Some salie nt features anti specific properties of this complex case gaugino "spectrum inversion" are illustrated and compared with a similar inversion in the re al case. In particular, our algorithms exhibit in a direct and transparent way the nontrivial theoretical correlation among the chargino and neutralin o parameters, and the resulting allowed domains when only a subset of the r equired physical input masses and production cross sections is known.