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 27.6 GeV at HERMES. These ratios were determined as a function of the virtual-photon energy v, its virtuality Q(2), the fractional hadron energy z and the transverse hadron momentum with respect to the virtual-photon direction p(t). 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 v as exhibited by pions and negative kaons. Protons were found to behave very differently from the other hadrons.