Measurement of the recoil polarization in the p (\vec e, e' \vec p) pi^0 reaction at the Δ(1232) resonance

Abstract

The recoil proton polarization has been measured in the p (\vec e,e'\vec p) pi^0 reaction in parallel kinematics around W = 1232 MeV, Q^2 = 0.121 (GeV/c)^2 and epsilon = 0.718 using the polarized c.w. electron beam of the Mainz Microtron. Due to the spin precession in a magnetic spectrometer, all three proton polarization components P_x/P_e = (-11.4 \pm 1.3 \pm 1.4) %, P_y = (-43.1 \pm 1.3 \pm 2.2) %, and P_z/P_e = (56.2 \pm 1.5 \pm 2.6) % could be measured simultaneously. The Coulomb quadrupole to magnetic dipole ratio CMR = (-6.4\pm 0.7_{stat}\pm 0.8_{syst}) % was determined from P_x in the framework of the Mainz Unitary Isobar Model. The consistency among the reduced polarizations and the extraction of the ratio of longitudinal to transverse response is discussed.

5 pages LaTeX, 1 table, 2 eps figures

References in corpus (3)

• Determination of the E2/M1 Ratio in the γN \to Δ(1232) Transition from a Simultaneous Measurement of p(\vecγ,p)π^0 and p(\vecγ,π^+)n
• A polarization relation and the measurement of the longitudinal response in pseudoscalar meson electroproduction off the nucleon
• Measuring longitudinal amplitudes for electroproduction of pseudoscalar mesons using recoil polarization in parallel kinematics

Cited by in corpus (67)

• Unitary Isobar Model - MAID2007
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• Explanation and Prediction of Observables using Continuum Strong QCD
• Electroexcitation of nucleon resonances
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• Study of Non-Strange Baryon Resonances with Meson Photoproduction
• Electromagnetic Excitation of Nucleon Resonances
• Nucleon and $\Delta$ elastic and transition form factors
• Investigation of the conjectured nucleon deformation at low momentum transfer
• The N to Delta electromagnetic transition form factors from Lattice QCD
• Chiral Effective-Field Theory in the Delta(1232) Region: Pion Electroproduction on the Nucleon
• Electroproduction of nucleon resonances
• Extraction and Interpretation of gamma N --> Delta Form Factors within a Dynamical Model
• The nucleon to Delta electromagnetic transition form factors in lattice QCD
• Electromagnetic Nucleon-to-Delta Transition in Chiral Effective-Field Theory
• Light baryon magnetic moments and N -> Delta gamma transition in a Lorentz covariant chiral quark approach
• D-state effects in the electromagnetic N-Delta transition
• Measurement of the Polarized Structure Function ${\sigma }_{L{T}^{\prime }}$ for $p(\vec{e},e^{\prime }p){\pi }^o$ in the $\Delta (1232)$ Resonance Region
• Lowest Q^2 Measurement of the gamma*p -> Delta Reaction: Probing the Pionic Contribution
• Elastic and transition form factors of the Δ(1232)
• Valence quark contribution for the gamma N -> Delta quadrupole transition extracted from lattice QCD
• Delta and Omega electromagnetic form factors in a Dyson-Schwinger/Bethe-Salpeter approach
• Electromagnetic N->Delta transition and neutron form factors
• Signatures of chiral dynamics in the Nucleon to Delta transition
• Measurement of the Polarized Structure Function ${\sigma }_{L{T}^{\prime }}$ for $p(\vec{e},e^{\prime }{\pi }^{+})n$ in the $\Delta (1232)$ Resonance Region
• Nucleon to Delta electromagnetic transition in the Dyson-Schwinger approach
• Measurement of the LT-asymmetry in π^0 electroproduction at the energy of the Δ(1232) resonance
• Measurement of the beam-helicity asymmetry in the p(e_pol,e'p)pi_0 reaction at the energy of the Delta(1232) resonance
• Insights into the gamma* N -> Delta transition
• Measurement of the Transverse-Longitudinal Cross Sections in the p (e,e'p)pi0 Reaction in the Delta Region
• Hadron structure at low Q^2
• Determination of quadrupole strengths in the gamma*p-->Delta(1232) transition at Q2= 0.20 (GeV/c)2
• Measurements of the gamma*p->Delta Reaction At Low Q^2: Probing the Mesonic Contribution
• Jülich-Bonn-Washington Model for Pion Electroproduction Multipoles
• Delta-baryon mass in a covariant Faddeev approach
• Recoil Polarization Measurements for Neutral Pion Electroproduction at Q^2=1 (GeV/c)^2 Near the Delta Resonance
• Electromagnetic Transition Form Factors of Baryon Resonances
• Deviation of the Nucleon Shape From Spherical Symmetry: Experimental Status
• Transition form factors: ${\gamma }^{\ast }+p\to \Delta (1232)$, $\Delta (1600)$
• Magnetic transitions and radiative decays of singly heavy baryons
• Neutral Pion Electroproduction in the Resonance Region at High $Q^2$
• The focal plane proton-polarimeter for the 3-spectrometer setup at MAMI
• Electromagnetic transition form factors of baryons in the space-like momentum region
• Study of polarized-e polarized-p --> e-prime p pi0 in the Delta(1232) mass region using polarization asymmetries
• Measurement of the R${}_{LT}$ response function for ${\pi }^0$ electroproduction at $Q^2$ = 0.070 (GeV/c)${}^2$ in the $N\to \Delta$ transition}
• Nucleon resonances with higher spins in soft-wall AdS/QCD
• A Study of Hadron Deformation in Lattice QCD
• Coupled-channel analysis of pion- and eta-electroproduction with the Jülich-Bonn-Washington model
• First Measurement of the Double Spin Asymmetry in $\vec{e}\vec{p}\to e^{\prime }{\pi }^{+}n$ in the Resonance Region
• Measurements of the γ* p --> Δ(1232) reaction at low Q2
• Electroexcitation of the ${\Delta }^{+}(1232)$ at low momentum transfer
• Virtual Compton Scattering measurements in the ${\gamma }^{\ast }N\to \Delta$ transition
• Baryon transition form factors at the pole
• Impact of JLab data on the determination of GPDs at zero skewness and new insights from transition form factors $N\to \Delta$
• Nucleon-to-Delta transition form factors in chiral effective field theory using the complex-mass scheme
• Virtual Compton Scattering measurements in the nucleon resonance region
• The Delta(1232) Resonance in Chiral Effective Field Theory
• Axial amplitudes for Delta excitation in chiral quark models
• Electromagnetic transition form factors, $E2/M1$ and $C2/M1$ ratios of the baryon decuplet
• Q^2-evolution of nucleon-to-resonance transition form factors in a QCD-inspired vector-meson-dominance model
• Direct calculation of the K-matrix for pion electro-production in the Delta channel
• Zero-Mode Contribution in Nucleon-Delta Transition
• Measurement of the Partial Cross Sections s(TT), s(LT) and [s(T)+epsilon*s(L)] of the p(e,e' pi+)n Reaction in the Delta(1232) Resonance
• Electromagnetic transition form factors of baryons in a relativistic Faddeev approach
• Pion electroproduction measurements in the nucleon resonance region
• Two-photon physics
• Axial-vector nucleon-to-delta transition form factors using the complex-mass renormalization scheme