Chiral symmetry and the reaction $\gamma p\to {\pi }^{0}p$

Abstract

We analyze the new threshold data for neutral pion photoproduction off protons in the framework of heavy baryon chiral perturbation theory. We show that large loop corrections are needed to understand the S--wave multipole $E_{0+}$ and that all pertinent low--energy constants can be understood within the framework of resonance exchange saturation. Previous inconsistencies in the description of this reaction in the threshold region are resolved.

8 pp, LaTeX/ReVTeX file, 3 figures (in a separate compressed tar files in pi0fig.uu)

References in corpus (4)

• Chiral Dynamics in Nucleons and Nuclei
• Aspects of Nucleon Compton Scattering
• Baryon Chiral Perturbation Theory A.D. 1994
• Kaon loops in pion photoproduction: Facts and fancy

Cited by in corpus (37)

• Chiral Perturbation Theory and Baryon Properties
• Effective Field Theory of Nuclear Forces
• Multipole analysis of pion photoproduction based on fixed t dispersion relations and unitarity
• Resonance saturation for four-nucleon operators
• Photon- and pion-nucleon interactions in a unitary and causal effective field theory based on the chiral Lagrangian
• Form factors and photoproduction amplitudes
• Photocouplings at the Pole from Pion Photoproduction
• Neutral pion photoproduction on deuterium in baryon chiral perturbation theory to order q^4
• Gauge-invariant approach to meson photoproduction including the final-state interaction
• Test of low-energy theorems for p(\vec{gamma},π^{0})p in the threshold region
• Redundance of $\Delta$-isobar Parameters in Effective Field Theories
• Chiral corrections to the Kroll-Ruderman theorem
• Improved description of threshold pion electroproduction in chiral perturbation theory
• Hadron structure at low Q^2
• Compton scattering from chiral dynamics with unitarity and causality
• A dispersion theoretical approach to the threshold amplitudes of pion photoproduction
• Model Selection for Pion Photoproduction
• Threshold kaon photo- and electroproduction in SU(3) baryon chiral perturbation theory
• Threshold ${\pi }^0$ photoproduction in relativistic chiral perturbation theory
• Pion photoproduction on nucleons in a covariant hadron-exchange model
• Radiative Muon Capture in Heavy Baryon Chiral Perturbation Theory
• The Fubini-Furlan-Rosetti sum rule and related aspects in light of covariant baryon chiral perturbation theory
• Double neutral pion photoproduction at threshold
• The Fubini-Furlan-Rossetti Sum Rule Revisited
• The reaction ${}^{2}H(\gamma ,{\pi }^0)np$ in the threshold region
• On neutral pion electroproduction off deuterium
• Hadron Structure in the Non-Perturbative Regime of QCD: Isospin Symmetry and its Violation
• Threshold pion electro- and photoproduction off nucleons in covariant chiral perturbation theory
• Chiral Perturbation Theory in Few-Nucleon Systems
• Considerations on rescattering effects for threshold photo- and electro-production of ${\pi }^0$ on deuteron
• Neutral weak currents in pion electroproduction on the nucleon
• A dispersive approach to pion photo- and electroproduction
• Kaon loops in pion photoproduction: Facts and fancy
• Neutral Pion Electroproduction on the Proton near Threshold
• Meson photoproduction at threshold in three flavor soliton models
• New developments in threshold pion photo- and electroproduction
• Threshold Neutral Pion Photoproduction on the Proton