fig. \[fig:exp\](a). In [@Boos:2005ca] detailed computations and Monte Carlo simulations for three different sets of MSSM parameters showed that a fit to the energy spectrum of the pion in the $\tau^{\pm}\to\pi^{\pm}\nu$ channel allows one to infer $M_{H^{\pm}}$ with an uncertainty at the level of $0.5$–$1$ GeV. In [@Godbole:2004mq] the prospects of using $\tau$ polarisation to probe the composition of $\tilde{\chi}^0_1$ from $\tilde\tau^+_1 \tilde\tau^-_1$ production at the ILC followed by $\tilde\tau^\pm_1 \rightarrow
 \tau^\pm \tilde{\chi}^0_1$ decay have been investigated. The $\tau$ polarization measurement, via its inclusive 1-prong hadronic decay, can discriminate SUSY models with different gaugino/higgsino decomposition of the neutralino. Fig. \[fig:exp\](b) shows the distribution of the fraction of the visible $\tau$-jet momentum carried by the charged prong, $R = p_{\pi^\pm}/p_{\tau-{\rm jet}}$, for four different theoretical models (for details we refer to [@Godbole:2004mq]).

(a)![(a) The $\pi^{\pm}$ energy spectrum from signal (solid line) and background (dotted line); from [@Boos:2005ca]. (b) The normalized distributions in the fraction of $\tau$-jet momentum carried by the charged track for $P_\tau$= +1, +1/2, $-$1/2 and $-$1, and $p^T_{\tau-jet} >$25 GeV; from [@Godbole:2004mq]. (c) Stop discovery reach in $\tilde{t}_1\to c\tilde{\chi}^0_1$ channel in the $m_{\tilde{t}_1}$-$m_{\tilde{\chi}^0_1}$ plane – the $t\to\tilde{t}_1\tilde{\chi}^0_1$ channel was not studied; from [@milstene]. (d) Effects of experimental constraints 