Measurement of multiplicity and momentum spectra in the current fragmentation region of the Breit frame at HERA

Charged particle production has been measured in Deep Inelastic Scattering (DIS) events using the ZEUS detector over a large range of $Q^2$ from 10 to $1280 {\rm\ GeV}^2$. The evolution with $Q$ of the charged multiplicity and scaled momentum has been investigated in the current fragmentation region of the Breit frame. The data are used to study QCD \linebreak coherence effects in DIS and are compared with corresponding \ee~data in order to test the universality of quark fragmentation.