1999/02/13 by C. Adloff, C. Adloff et al. · 8 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1007/s100520050703
published as Eur.Phys.J.C13:371-396,2000 · 55 pages, 24 figures, 13 tables submitted to Eur. Phys. J C
arxiv created 1999/02/13 · openalex publication_date 2000/01/01 · arxiv updated 2009/11/30 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/01
The elastic electroproduction of rho mesons is studied at HERA with the H1 detector for a photon virtuality in the range 1 < Q2 < 60 GeV2 and for a hadronic centre of mass energy in the range 30 < W < 140 GeV. The shape of the pipi mass distribution in the rho resonance region is measured as a function of Q2. The full set of rho spin density matrix elements is determined, and evidence is found for a helicity flip amplitude at the level of 8 +- 3 % of the non-flip amplitudes. Measurements are presented of the dependence of the cross section on Q2, W and t (the four-momentum transfer squared to the proton). They suggest that, especially at large Q2, the gamma^*p cross section develops a stronger W dependence than that expected from the behaviour of elastic and total hadron-hadron cross sections.