  We present the first three-fold differential measurement for neutral pion
multiplicity ratios produced in semi-inclusive deep-inelastic electron
scattering on carbon, iron and lead nuclei normalized to deuterium from CLAS at
Jefferson Lab. We found that the neutral pion multiplicity ratio is maximally
suppressed for the leading hadrons (energy fraction z approaching unity),
suppression varying from 25% in carbon up to 75% in lead. An enhancement of the
multiplicity ratio at low z and high p2T is observed, suggesting an
interconnection between these two variables. This behavior is qualitatively
similar to the previous two-fold differential measurement of charged pions by
the HERMES Collaboration and recently - by CLAS Collaboration. The largest
enhancement was observed at high pT2 for heavier nuclei, namely iron and lead,
while the smallest enhancement was observed for the lightest nucleus, carbon.
This behavior suggests a competition between partonic multiple scattering,
which causes enhancement, and hadronic inelastic scattering, which causes
suppression.
