Exclusive Meson Photo- and Electro-production, a Window on the Structure of Hadronic Matter

Abstract

At high energy, exclusive meson photo- and electro-production give access to the structure of hadronic matter. At low momentum transfers, the exchange of a few Regge trajectories leads to a comprehensive account of the cross-sections. Among these trajectories, which are related to the mass spectrum of families of mesons, the Pomeron plays an interesting role as it is related to glue-ball excitations. At high momentum transfers, the exchange of these collective excitations is expected to reduce to the exchange of their simplest (quark or gluon) components. However, contributions from unitarity rescattering cuts are relevant even at high energies. In the JLab energy range, the asymptotic regime, where the players in the game are current quarks and massless gluons has not been reached yet. One has to rely on more effective degrees of freedom adapted to the scale of the probe. A consistent picture, the Partonic Non-Perturbative Regime, is emerging. The properties of its various components (dressed propagators, effective coupling constants, quark wave functions, shape of the Regge trajectories, etc) provide us with various links to hadron properties. I will review the status of the field, will put in perspective the current achievements at JLab, SLAC and Hermes, and will assess future developments that are made possible by continuous electron beams at higher energies.

arXiv comment56 pages, 42 figures, review article. Three slips corrected (15/02/2020): i) correct sign in the definition of Q2, in the third paragraph of Intro; ii) ç in the name Garçon, in the laTex file (Acknowledgement section) iii) one grammatical slip

References in corpus (33)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• Factorization for hard exclusive electroproduction of mesons in QCD
• Measurement of the Beam-Spin Azimuthal Asymmetry Associated with Deeply-Virtual Compton Scattering
• Differential Cross Sections for gamma + p --> K+ + Y for Lambda and Sigma0 Hyperons
• First measurement of near-threshold J/$\psi$ exclusive photoproduction off the proton
• Elastic Photoproduction of J/psi and Upsilon Mesons at HERA
• Scaling Tests of the Cross Section for Deeply Virtual Compton Scattering
• The Beam--Charge Azimuthal Asymmetry and Deeply Virtual Compton Scattering
• Photoproduction of charm near threshold
• The E00-110 experiment in Jefferson Lab's Hall A: Deeply Virtual Compton Scattering off the Proton at 6 GeV
• Photoproduction of Vector Mesons at Large Transfer
• Photoproduction of phi(1020) mesons on the proton at large momentum transfer
• Cross sections for hard exclusive electroproduction of pi+ mesons on a hydrogen target
• Exclusive ${\rho }^0$ electroproduction on the proton at CLAS
• DRAFT: Photoproduction of the ${\rho }^0$ meson on the proton at large momentum transfer
• Photoproduction of the $\omega$ meson on the proton at large momentum transfer
• Deeply virtual and exclusive electroproduction of omega mesons
• The space-time structure of hard scattering processes
• A Consistent Next-to-Leading-Order QCD Calculation of Hadronic Diffractive Scattering
• Exclusive Neutral Pion Electroproduction in the Deeply Virtual Regime
• Deep exclusive charged $\pi$ electroproduction above the resonance region
• Electroproduction of $\varphi (1020)$ mesons at $1.4\le Q^2\le$ GeV${}^2$ measured with the CLAS spectrometer
• Compton scattering, vector meson photoproduction and the partonic structure of the nucleon
• The Primakoff effect on a proton target
• Real and Virtual Compton Scattering in a Regge Approach
• Unitarity constraints on neutral pion electroproduction
• Deep exclusive ${\pi }^{+}$ electroproduction off the proton at CLAS
• Exclusive photoproduction of ${\pi }^0$ up to large values of Mandelstam variables $s,t$ and $u$ with CLAS
• Rescattering in Meson Photoproduction off Few Body Systems
• Unitary constraints on Deeply Virtual Compton Scattering
• Tensor Polarization of the phi meson Photoproduced at High t
• Unitarity constraints on charged pion photoproduction at large p_perp
• Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton

Cited by in corpus (8)

• XYZ spectroscopy at electron-hadron facilities: Exclusive processes
• Transition distribution amplitudes and hard exclusive reactions with baryon number transfer
• Progress and Opportunities in Backward angle (u-channel) Physics
• u-Channel Color Transparency Observables
• Differential cross sections and photon beam asymmetries of $\eta$ photoproduction on the proton at $E_{\gamma }$ = 1.3-2.4 GeV
• Unitarity constraints on meson electroproduction at backward angles
• Combined analysis of the $\gamma n\to K^0{\Sigma }^0$ and $\gamma n\to K^{+}{\Sigma }^{-}$ reactions
• Probing hard/soft factorization via beam-spin asymmetry in exclusive pion electroproduction from the proton