  The scalar top discovery potential has been studied for the TESLA project
with a full-statistics background simulation at sqrt(s)=500 GeV and L=500 fb-1.
The beam polarization is very important to measure the scalar top mixing angle
and to determine its mass. The latest estimation of the beam polarization
parameters is applied. This study includes e+ polarization, which improves the
sensitivity. For a 180 GeV scalar top at minimum production cross section, we
obtain Delta(m)=0.8 GeV and Delta(cos(Theta))=0.008 in the neutralino channel,
and Delta(m)=0.5 GeV and Delta(cos(Theta))=0.004 in the chargino channel. The
MSSM parameters for the Snowmass point 5 at cos(Theta)=0.513 predict a scalar
top of 210 GeV and a neutralino of about 120 GeV. For this parameter choice
Delta(m)=0.95 GeV and Delta(cos(Theta))=0.0125 is obtained, and a preliminary
c-tagging study is presented in the neutralino channel.
