Scaled momentum spectra in deep inelastic scattering at HERA

TL;DR

This paper investigates charged particle production in deep inelastic scattering at HERA, analyzing scaled momentum spectra and their evolution with photon virtuality, and compares results with QCD calculations, Monte Carlo models, and e+e- data.

Contribution

It provides detailed measurements of scaled momentum spectra in the Breit frame and compares them with theoretical models and e+e- data, enhancing understanding of particle production in DIS.

Findings

Spectra evolve with Q^2 in the studied range.

QCD calculations and Monte Carlo models describe the data reasonably well.

Results support the limiting fragmentation hypothesis.

Abstract

Charged particle production has been studied in neutral current deep inelastic ep scattering with the ZEUS detector at HERA using an integrated luminosity of 0.44 fb^-1. Distributions of scaled momenta in the Breit frame are presented for particles in the current fragmentation region. The evolution of these spectra with the photon virtuality, Q^2, is described in the kinematic region 10<Q^2<41000 GeV^2. Next-to-leading-order and modified leading-log-approximation QCD calculations as well as predictions from Monte Carlo models are compared to the data. The results are also compared to e+e- annihilation data. The dependences of the pseudorapidity distribution of the particles on Q^2 and on the energy in the \gamma p system, W, are presented and interpreted in the context of the hypothesis of limiting fragmentation.