Exclusive rho-0 electroproduction on transversely polarized protons

Abstract

The exclusive electroproduction of rho-0 mesons was studied with the HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and electron beams off a transversely polarized hydrogen target. Spin density matrix elements for this process were determined from the measured production- and decay-angle distributions of the produced rho-0 mesons. These matrix elements embody information on helicity transfer and the validity of s-channel helicity conservation in the case of a transversely polarized target. From the spin density matrix elements, the leading-twist term in the single-spin asymmetry was calculated separately for longitudinally and transversely polarized rho-0 mesons. Neglecting s-channel helicity changing matrix elements, results for the former can be compared to calculations based on generalized parton distributions, which are sensitive to the contribution of the total angular momentum of the quarks to the proton spin.

7 pages, 5 figures

References in corpus (17)

• High-Energy-Physics Event Generation with PYTHIA 6.1
• Gauge-Invariant Decomposition of Nucleon Spin and Its Spin-Off
• Wave Functions, Evolution Equations and Evolution Kernels from Light-Ray Operators of QCD
• Generalized Parton Distributions
• Deeply Virtual Compton Scattering
• Nonforward Parton Distributions
• Unraveling hadron structure with generalized parton distributions
• Hard Exclusive Reactions and the Structure of Hadrons
• Factorization for hard exclusive electroproduction of mesons in QCD
• Scaling Limit of Deeply Virtual Compton Scattering
• The HERMES Spectrometer
• The HERMES Polarized Hydrogen and Deuterium Gas Target in the HERA Electron Storage Ring
• The target asymmetry in hard vector-meson electroproduction and parton angular momenta
• Spin Density Matrix Elements in Exclusive rho^0 Electroproduction on 1H and 2H Targets at 27.5 GeV Beam Energy
• Next-to-leading order corrections in exclusive meson production
• Vector meson production from a polarized nucleon
• Can the total angular momentum of u-quarks in the nucleon be accessed at HERMES?

Cited by in corpus (17)

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• Nucleon structure from mixed action calculations using 2+1 flavors of asqtad sea and domain wall valence fermions
• Insights into the Emergence of Mass from Studies of Pion and Kaon Structure
• From hard exclusive meson electroproduction to deeply virtual Compton scattering
• The Hadronic Final State at HERA
• Towards a fitting procedure to deeply virtual meson production -- the next-to-leading order case --
• Transverse target spin asymmetries in exclusive ${\rho }^0$ muoproduction
• Exclusive rho^0 muoproduction on transversely polarised protons and deuterons
• Status of DVMP, DVCS and GPDs
• Ratios of helicity amplitudes for exclusive ${\rho }^0$ electroproduction on transversely polarized protons
• Extracting transition generalized parton distributions from hard exclusive pion-nucleon scattering
• Double Helicity Dependence of Jet Properties from Dihadrons in Longitudinally Polarized p+p Collisions at sqrt(s) = 200 GeV
• Transverse target single-spin asymmetry in inclusive electroproduction of charged pions and kaons
• Generalized parton distributions from meson leptoproduction
• Generelized Parton Distributions in light meson production
• DVCS at HERMES
• Spin effects in hard exclusive electroproduction of mesons