The simulation input is a list of events, each of which contains a list of particles and their momenta.
This list may be generated by Monte Carlo event generators,
which produce distributions of particle species and momenta that approximate the physical
distributions (Venus, UrQMD, Fritiof), or by "hand" according to any other
distribution. For embedding studies, the event of MC particles is usually generated by "hand"
with a fixed number of particles per event of a single species and with a parametrized momentum
distributions ("Micky Mouse" simulation).
These distributions can either be a parametrization of realistic particle distributions or can
also be flat in phasespace.
The latter option has the advantage that correction factors calculated
from the embedding procedure have
comparable statistical significance for all y-pt bins.
In order to take the real phasespace population into accoun, the input particles should
be given weights according to the realistic distributions when calculating the final
you can see as an example a simple "Micky Mouse"
simulation of K* production
of the model "Venus"