Charged Particle Production in High Q2 Deep-Inelastic Scattering at HERA

TL;DR

This paper measures charged particle production in high Q2 deep-inelastic scattering at HERA, providing high-precision data across a broad phase space and comparing it with e+e- data and QCD models.

Contribution

It offers the most precise measurements to date of charged particle multiplicities and momentum distributions at high Q2, extending previous analyses and testing QCD predictions.

Findings

Charged particle multiplicities increase with Q2.

Distribution of scaled momentum matches QCD models.

Results extend phase space coverage significantly.

Abstract

The average charged track multiplicity and the normalised distribution of the scaled momentum, $\xp$, of charged final state hadrons are measured in deep-inelastic $\ep$ scattering at high $Q^2$ in the Breit frame of reference. The analysis covers the range of photon virtuality $100 < Q^2 < 20 000 \GeV^{2}$. Compared with previous results presented by HERA experiments this analysis has a significantly higher statistical precision and extends the phase space to higher $Q^{2}$ and to the full range of $\xp$. The results are compared with $e^+e^-$ annihilation data and with various calculations based on perturbative QCD using different models of the hadronisation process.