Study of Elastic rho0 photoproduction at HERA using the ZEUS Leading Proton Spectrometer

Abstract

The differential cross section $d\sigma /dt$ for elastic ${\rho }^0$ photoproduction, $\gamma p\to {\rho }^{0}p({\rho }^0\to {\pi }^{+}{\pi }^{-})$, has been measured in $ep$ interactions at HERA. The squared four-momentum exchanged at the proton vertex, $t$, has been determined directly by measuring the momentum of the scattered proton using the ZEUS Leading Proton Spectrometer (LPS), a large scale system of silicon micro-strip detectors operating close to the HERA proton beam. The LPS allows the measurement of the momentum of high energy protons scattered at small angles with accuracies of 0.4% for the longitudinal momentum and 5 MeV for the transverse momentum. Photoproduction of ${\rho }^0$ mesons has been investigated in the interval $0.073<|t|<0.40Ge{V}^2$, for photon virtualities $Q^2<1Ge{V}^2$ and photon-proton centre-of-mass energies $W$ between 50 and 100 GeV. In the measured range, the $t$ distribution exhibits an exponential shape with a slope parameter $b=9.8\pm 0.8(stat.)\pm 1.1(syst.)Ge{V}^{-2}$. The use of the LPS eliminates the contamination from events with diffractive dissociation of the proton into low mass states.

38 pages including 13 figures

References in corpus (2)

• Measurement of the Cross Section for the Reaction $γp \to \jpsi~p$ with the ZEUS Detector at HERA
• Exclusive ${\rho }^0$ production in deep inelastic electron-proton scattering at HERA

Cited by in corpus (33)

• Leading proton production in deep inelastic scattering at HERA
• A measurement of the Q^2, W and t dependences of deeply virtual Compton scattering at HERA
• Diffractive Electroproduction of rho and phi Mesons at HERA
• HERA Collider Physics
• Exclusive rho^0 production in deep inelastic scattering at HERA
• Color Transparency versus Quantum Coherence in Electroproduction of Vector Mesons off Nuclei
• Dissociation of virtual photons in events with a leading proton at HERA
• The Hadronic Final State at HERA
• The design and performance of the ZEUS Micro Vertex detector
• Deep inelastic scattering with leading protons or large rapidity gaps at HERA
• Measurement of exclusive omega electroproduction at HERA
• Leading proton production in e^+p collisions at HERA
• Nuclear shadowing in photoproduction of $\rho$ mesons in ultraperipheral nucleus collisions at RHIC and the LHC
• Leading neutron energy and pT distributions in deep inelastic scattering and photoproduction at HERA
• Photo-production of psi' Mesons at HERA
• Vector Meson Photoproduction with a Linearly Polarized Beam
• Selected topics in diffraction with protons and nuclei: past, present, and future
• Review of High Energy Diffraction in Real and Virtual Photon Proton scattering at HERA
• Fermi Motion and Quark Off-Shellness in Elastic Vector-Meson Production
• Unifying "soft" and "hard" diffractive exclusive vector meson production and deeply virtual Compton scattering
• Study of the pion trajectory in the photoproduction of leading neutrons at HERA
• The Wave Function of 2S Radially Excited Vector Mesons from Data for Diffraction Slope
• The ground state of the Pomeron and its decays to light mesons and photons
• Production of Polarized Vector Mesons off Nuclei
• Properties of hadronic final states in diffractive deep inelastic ep scattering at HERA
• Visualizations of the Exclusive Central Diffraction
• Color Dipole Systematics of the Diffraction Slope in Diffractive Photo- and Electroproduction of Vector Mesons
• Diffractive longitudinal structure function at the Electron Ion Collider
• Probing Quantum Phenomena through Photoproduction in Relativistic Heavy-Ion Collisions
• Nonlinearity of vacuum reggeons and exclusive diffractive production of vector mesons at HERA
• Novel features in exclusive vector--meson production
• Diffractive phenomena
• A simple model for high-energy nucleon-nucleon elastic diffraction and exclusive diffractive electroproduction of vector mesons on protons