Conclusions

The scaled momentum distributions of final state charged hadrons have been measured in the current region of the Breit frame over a wide range of values of Q². The ZEUS data are consistent with the predictions of scaling violations at high Q² and high x_p. The results are in good agreement with results from e⁺e^- experiments and also with a NLO calculation using input fragmentation functions from e⁺e^- data, indicating strong support for the concept of the universality of quark fragmentation.

  

Figure 1: The corrected scaled momentum distributions from ZEUS 1994 data compared with the generated distributions from the Monte Carlo (ARIADNE 4.03). Statistical errors only are shown.

  

Figure: The inclusive charged particle distribution, 1/$\sigma_{tot}^{}$ d$\sigma$/dx_p, in the current region of the Breit frame. The filled points are ZEUS data, and the statistical (thick error bars) and combined statistical and systematic (thin error bars) errors are shown. The open points represent the data from e⁺e^- experiments corrected for contributions from K⁰_S and $\Lambda$ decays. The lines show the NLO predictions.