  Clusterization in phase space has been analyzed for peripheral Au+Au
reactions at 1000 AMeV using simulated annealing clusterization algorithm
(SACA). We investigate how these fragments are correlated in phase space and
compare our model calculations with minimum spanning tree (MST) method. Our
theoretical study highlights the importance of binding energy criterion in
recognizing the fragment structure. MST method however, fails to break-up the
spectator matter effectively and thus under-estimates the multiplicity of
intermediate mass fragments (IMFs).
