Deeply Virtual Compton Scattering at HERA II (H1 results)

TL;DR

This paper presents new measurements of the DVCS process at HERA II, analyzing the cross section dependence on key variables and comparing results with theoretical models, thereby enhancing understanding of proton structure.

Contribution

It provides the first detailed DVCS cross section measurements at HERA II with improved data and compares results to advanced QCD models and previous experiments.

Findings

DVCS cross sections measured across a broad kinematic range.

Results agree well with previous H1 and ZEUS measurements.

Data align with NLO QCD and Color Dipole Model predictions.

Abstract

New results on the Deeply Virtual Compton Scattering process $\gamma^* p \to \gamma p$ (DVCS) from H1 experiment at the $e p$ collider HERA are presented, using data collected during the year 2004 and corresponding to an integrated luminosity of 39.7 pb$^{-1}$. The DVCS cross section is measured as a function of the photon virtuality, $Q^2$, the $\gamma^* p $ c.m.s. energy $W$ and differentially in the momentum transfer squared at the proton vertex, $t$, in the kinematic range $6.5 < Q^2 < 80 $ GeV$^2$, $30 < W < 140$ GeV and $|t| < 1$ GeV$^2$. The results are found to be in good agreement with the published H1 and ZEUS measurements and compared to NLO QCD calculations based on Generalized Parton Distributions (GPD) and to predictions from Color Dipole Model.