  Scale invariant presentation of inclusive spectra in terms of light front
variables is proposed. The variables introduced go over to the well-known
scaling variables x_F = 2p_z/sqrt(s) and x_T=2p_T/sqrt{s} in the high p_z and
high p_T limits respectively. So Some surface is found in the phase space of
produced pi-mesons in the inclusive reaction anti p p -> pi+- X at 22.4 GeV/c,
which separates two groups of particles with significantly different
characteristics. In one of these regions a naive statistical model seems to be
in a good agreement with data, whereas it fails in the second region. Key
words: Light front, inclusive, hadron-hadron, electron-positron, relativistic
heavy ions, deep inelastic.
