Particle production at HERA

TL;DR

This paper presents recent experimental results from HERA on hadronic final states, including strangeness production, correlations, polarization, Bose-Einstein effects, heavy particle searches, anti-deuteron production, and azimuthal asymmetries, comparing them with theoretical models.

Contribution

It provides new measurements and analyses of various hadronic phenomena at HERA, including strangeness, polarization, correlations, and searches for heavy particles, enhancing understanding of QCD processes.

Findings

No significant $ar{ ext{Lambda}}$ asymmetry observed.

Azimuthal asymmetries match perturbative QCD predictions.

Anti-deuteron production cross section measured.

Abstract

Recent results on the properties of the hadronic final state at the HERA collider are presented. Strangeness production and correlations have been studied in the laboratory system for deep inelastic scattering (DIS). Inclusive $K^0_S$, $\Lambda$ and $\bar{\Lambda}$ production has been measured and compared to Monte Carlo model calculations. No significant $\Lambda$ to $\bar{\Lambda}$ production asymmetry was observed and the measured $\Lambda (\bar{\Lambda})$ polarisations are consistent with zero. Bose-Einstein correlations between charged and neutral kaons have been studied and the obtained results are compared with the LEP measurements. A search for heavy particles was performed in the photoproduction process. The cross section for anti-deuteron production has been measured at a mean center-of-mass energy of $W_{\gamma p}$ = 200 GeV. The azimuthal angle distribution of hadrons in DIS has also been studied in the hadronic center-of-mass system. The measurements of the azimuthal asymmetry are consistent with the perturbative QCD predictions.