Multidimensional study of hadronization in nuclei

Hadron multiplicities in semi-inclusive deep-inelastic scattering were measured on neon, krypton, and xenon targets relative to deuterium at an electron(positron)-beam energy of 27.6GeV at HERMES. These ratios were determined as a function of the virtual-photon energy \( \nu\) , its virtuality Q2, the fractional hadron energy z and the transverse hadron momentum with respect to the virtual-photon direction pt. Dependences were analysed separately for positively and negatively charged pions and kaons as well as protons and antiprotons in a two-dimensional representation. Compared to the one-dimensional dependences, some new features were observed. In particular, when z > 0.4 positive kaons do not show the strong monotonic rise of the multiplicity ratio with \( \nu\) as exhibited by pions and negative kaons. Protons were found to behave very differently from the other hadrons.