  Sleptons can easily be found at future linear e+e- colliders if kinematically
accessible. Measurements of their masses and decay distributions would then
determine MSSM parameters. This paper presents a detailed MC study of the
production and decay of the lighter scalar tau lepton, stau1. We found that
mstau1 and the left-right mixing angle of stau would be measured within an
error of a few percent. tanbeta is determinable in some region of the parameter
space through simultaneous studies of stau1-and selectron-pair production: the
polarization measurement of the tau leptons from stau1 decays and the M1, mchi1
determination using selectron pair production and decay. We also point out the
possibility to determine bino-selectron-e coupling through the measurement of
the angular distribution of the selectron-pair production. The error on the
coupling is expected to be comparable to its typical SUSY radiative correction,
which is proportional to log(msquark/mslepton). The radiative correction
affects M1 and tanbeta determination, necessitating the full 1-loop radiative
correction to the selectron production processes. The implication of these
measurements of the MSSM parameters on selecting models of the origin of
supersymmetry breaking is also discussed.
