Polarization of the τ lepton from scalar τ decay as a probe of neutralino mixing

The τ lepton arising from the scalar tau (τ̃) decay is naturally polarized. ${\mathit{P}}_{\mathrm{\tau }}$ depends on the left-right mixing of the τ̃ and the gaugino-Higgsino mixing of the neutralino. The polarization ${\mathit{P}}_{\mathrm{\tau }}$ could be measured from the energy distribution of the decay products of τ at future ${\mathit{e}}^{+}$ ${\mathit{e}}^{\mathrm{-}}$ colliders. A measurement of ${\mathit{P}}_{\mathrm{\tau }}$ and of the τ̃ production cross section allows us to determine both these mixing angles.