Accurate Test of Chiral Dynamics in the \boldmath$\vec{\gamma }p\to {\pi }^{0}p$ Reaction

Abstract

A precision measurement of the differential cross sections $d\sigma /d\Omega$ and the linearly polarized photon asymmetry $Σ\equiv (dσ_\perp - dσ_\parallel) \slash (dσ_\perp + dσ_\parallel)$ for the $\vec{\gamma }p\to {\pi }^{0}p$ reaction in the near-threshold region has been performed with a tagged photon beam and almost $4\pi$ detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multi-photon detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the $S$- and all three $P$-wave amplitudes for the first time and provide the most stringent test to date of the predictions of Chiral Perturbation Theory and its energy region of agreement with experiment.

5 pages, 2 figures

References in corpus (9)

• Chiral Perturbation Theory and Baryon Properties
• Upgrade of the Glasgow photon tagging spectrometer for Mainz MAMI-C
• Chiral perturbation theory
• Isospin breaking in the pion-nucleon scattering lengths
• Determination of the Dalitz plot parameter alpha for the decay eta->3pi^0 with the Crystal Ball at MAMI-B
• Threshold ${\pi }^0$ photoproduction in relativistic chiral perturbation theory
• Properties of Nucleon Resonances by means of a Genetic Algorithm
• Upper Energy Limit of Heavy Baryon Chiral Perturbation Theory in Neutral Pion Photoproduction
• Low-Energy D-Wave Effects in Neutral Pion Photoproduction

Cited by in corpus (30)

• QCD and strongly coupled gauge theories: challenges and perspectives
• Photocouplings at the Pole from Pion Photoproduction
• Light Baryon Spectroscopy
• Photoproduction Reactions and Non-Strange Baryon Spectroscopy
• Measurement of pi^0 photoproduction on the proton at MAMI C
• Model Selection for Pion Photoproduction
• Measurement of the pi^0 -> e^+e^-gamma Dalitz decay at the Mainz Microtron
• Cross Section for $\gamma n\to {\pi }^{0}n$ measured at Mainz/A2
• Upper Energy Limit of Heavy Baryon Chiral Perturbation Theory in Neutral Pion Photoproduction
• Determining the dominant partial wave contributions from angular distributions of single- and double-polarization observables in pseudoscalar meson photoproduction
• $\Delta (1232)$ resonance in the $\vec{\gamma }p\to p{\pi }^0$ reaction at threshold
• Pion photoproduction off nucleons in covariant chiral perturbation theory
• Near-threshold ${\pi }^{-}$ photoproduction on the deuteron
• Threshold pion electro- and photoproduction off nucleons in covariant chiral perturbation theory
• Moravcsik's theorem on complete sets of polarization observables reexamined
• Photon asymmetry measurements of $\overrightarrow{\gamma }\mathrm{p}\to {\pi }^0\mathrm{p}$ for E${}_{\gamma }$=320$-$650 MeV
• Fixed-t analyticity as a constraint in single energy partial wave analyses of meson photoproduction reactions
• The complete experiment problem of pseudoscalar meson photoproduction in a truncated partial wave analysis
• Single-Energy Partial Wave Analysis for ${\pi }^0$ Photoproduction on Proton with Fixed-$t$ Analyticity Imposed
• Single-energy partial wave analysis for pion photoproduction with fixed-t analyticity
• A precision measurement of the $p$($e,e^{\prime }p$)${\pi }^0$ reaction at threshold
• Pions: Experimental Tests of Chiral Symmetry Breaking
• New Analysis of Threshold Photoproduction Data from MAMI
• Pion photo- and electroproduction and the chiral MAID interface
• The Upper Energy Limit of HBChPT in Pion Photoproduction
• Pion Photo- and Electroproduction and the Chiral MAID Interface
• New high-statistics measurement of the ${\pi }^0\to e^{+}{e}^{-}\gamma$ Dalitz decay at the Mainz Microtron
• Pion photo- and electroproduction in relativistic baryon ChPT
• New graphical criterion for the selection of complete sets of polarization observables and its application to single-meson photoproduction as well as electroproduction
• Threshold Neutral Pion Photoproduction on the Proton