Speaker
Description
The direct pair-production of the superpartner of the $\tau$-lepton, the $\widetilde{\tau}$,
is one
of the most interesting channels to search for SUSY in:
the $\widetilde{\tau}$ is
likely to be the lightest of the scalar leptons,
and is one of the most experimentally challennging ones.
The current model-independent $\widetilde{\tau}$ limits come from LEP,
while limits obtained at the LHC do extend to higher masses, but are model-dependent.
The future Higgs factories will be powerful facilities for SUSY searches, offering advantages
with respect to previous electron-positron colliders as well as to hadron machines.
In order to quantify the capabilities of these future $e^+e^-$ colliders,
the ``worst-case'' scenario for $\widetilde{\tau}$ exclusion/discovery has been studied, taking
into account the effect of the $\widetilde{\tau}$ mixing on $\widetilde{\tau}$ production
cross-section and detection efficiency.
To evaluate the latter, the ILD concept, originally developed for the International
Linear Collider (ILC), and the ILC beam conditions at a centre-of-mass energy of
$500$\,GeV have been used for detailed simulations.
The obtained exclusion and discovery reaches extend to only a few GeV below the kinematic limit
even in the worst-case scenario.
A recast of the results of the detailed simulation study to ILC at different CM energies,
and to the experimental environment of other proposed Higgs factory projects is also
presented.
