Photoproduction of K^0 and Lambda at HERA and a Comparison with Deep Inelastic Scattering

TL;DR

This paper investigates inclusive $K^0$ and $\Lambda$ photoproduction at HERA, comparing the results with deep inelastic scattering, $par p$ data, and theoretical models to understand strangeness production mechanisms.

Contribution

It provides the first detailed comparison of strangeness photoproduction rates and spectra with deep inelastic scattering and theoretical predictions at high energies.

Findings

Photoproduction rates are similar to those in deep inelastic scattering.

Strangeness production rates are consistent with $par p$ measurements.

Data agree with next-to-leading order QCD calculations and Monte Carlo models.

Abstract

Inclusive $K^0$ and $\Lambda$ photoproduction has been investigated at HERA with the H1 detector at an average photon-proton center of mass energy of 200 GeV in the transverse momentum range 0.5 <p_t <5 GeV. The production rates as a function of $p_t$ and center of mass rapidity are compared to those obtained in deep inelastic scattering at $\av{Q^2}=23 GeV^2$. A similar comparison is made of the rapidity spectra of charged particles. The rate of strangeness photoproduction is compared with $p\bar p$ measurements. The observations are also compared with next-to-leading order QCD calculations and the predictions of a Monte Carlo model.