...
Stdhep files for an Ecm=500 GeV SM data sample are
available at ftp://ftp-lcd.slac.stanford.edu/ilc/ILC500/StandardModel/ .
There are 487,603,537 events (250 fb-1 luminosity) with -80% electron/ +30% positron polarization,
and 474,837,805 events (250 fb-1 luminosity) with +80% electron/ -30% positron polarization.
Due to the presence of many high cross section processes the events are not completely unweighted.
The event weight must therefore always be considered when analyzing events.
This weight stored in the variable EVENTWEIGHTLH in the stdhep common block HEPEV4.