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.

arXiv comment5 pages LaTeX, 1 table, 2 eps figures

References in corpus (8)

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Cited by in corpus (67)

• Unitary Isobar Model - MAID2007
• Electromagnetic excitation of the Delta(1232)-resonance
• Explanation and Prediction of Observables using Continuum Strong QCD
• Electroexcitation of nucleon resonances
• $Q^2$ Dependence of Quadrupole Strength in the ${\gamma }^{\ast }p\to {\Delta }^{+}(1232)\to p{\pi }^0$ Transition
• 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