Hadronization in the Nuclear Media

The influence of the nuclear environment on the production of charged pions, kaons and (anti)protons in semi-inclusive deep inelastic scattering has been studied by the HERMES experiment at DESY using a 27.6 GeV positron beam. Identified hadron multiplicities have been measured for helium, neon, krypton and xenon relative to that of deuterium as a function of ν, z and pt2. Dependences have been extracted in a one and two-dimensional representation, i. e. in the form of detailed binning over one variable and integrating over all other variable or three slices over the other variable. The most prominent feauteres compared to a one-dimensional analysis are changes of the ν-, pt2 two-dimensional dependences of ratios, in particular in case of protons. In general pions and negative kaons show similar dependences, however, positive kaons, protons and antiprotons behave quite differently. (author)