Diffractive Rho Meson Electroproduction at High Q^2 and High |t|

TL;DR

This paper investigates rho meson electroproduction at high Q^2 and |t| at HERA, measuring cross sections and spin density matrix elements to understand the transition from soft to hard QCD processes.

Contribution

It provides new measurements of cross sections and spin density matrix elements at high Q^2 and |t|, comparing them with a two gluon exchange model.

Findings

W dependence increases with Q^2, indicating a transition from soft to hard processes.

Measured spin density matrix elements show agreement with two gluon exchange predictions.

Cross sections vary with Q^2, W, and t, revealing insights into the underlying QCD dynamics.

Abstract

The electroproduction of rho mesons is studied at HERA with the H1 detector at high Q^2 and high |t|. Cross sections are measured as a function of Q^2, W and t. The W dependence of the gamma*-p cross section is observed to increase with Q^2 from values compatible with soft Pomeron exchange at low Q^2 to a hard dependence at large Q^2. Spin density matrix elements are measured and their dependence is compared with a two gluon exchange model.