Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

TL;DR

This paper investigates forward pi^0 meson production and associated transverse energy flow in deep-inelastic scattering at HERA, comparing experimental data with QCD-based models to enhance understanding of parton dynamics at very low Bjorken-x.

Contribution

It provides new measurements of forward pi^0 production and transverse energy flow at unprecedented low Bjorken-x, testing different QCD evolution schemes against experimental data.

Findings

Measured inclusive cross sections for forward pi^0 production.

Observed transverse energy flow in events with forward pi^0.

Compared data with QCD models, highlighting their strengths and limitations.

Abstract

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.