  With the experimental data from STAR on the centrality dependence of
transverse momentum $p_T$ spectra of pions and protons in Au+Au collisions at
$\sqrt{s_{NN}}=200 {\rm GeV}$, we investigate the scaling properties of
transverse energy $E_T$ distributions at different centralities. In the
framework of cluster formation and decay mechanism for particle production, the
universal transverse energy distributions for pion and proton can be described
separately but not simultaneously.
