Measurement of multiplicity and momentum spectra in the current and target regions of the Breit frame in Deep Inelastic Scattering at HERA

TL;DR

This study analyzes charged particle production in deep inelastic scattering at HERA, examining how multiplicities and momentum spectra evolve with energy scales in different regions, and compares data to theoretical predictions.

Contribution

It provides the first comparison of target region distributions with current region data in the Breit frame at HERA, testing MLLA and LPHD predictions against experimental results.

Findings

Distributions in the target region differ from the current region.

MLLA and LPHD predictions do not match the observed data.

Charged particle spectra evolve with Q^2 and x in both regions.

Abstract

Charged particle production in neutral current deep inelastic scattering (DIS) has been studied using the ZEUS detector.The evolution of the mean multiplicities, scaled momenta and transverse momenta in $Q^2$ and $x$ for $ 10 < Q^2 < 5120 GeV^2$ and $x > 6\times 10^{-4}$ has been investigated in the current and target fragmentation regions of the Breit frame. Distributions in the target region, using HERA data for the first time, are compared to distributions in the current region. Predictions based on MLLA and LPHD are inconsistent with the data.