Induced proton polarization for pi^0 electroproduction at Q^2 = 0.126 (GeV/c)^2 around the Delta(1232) resonance

Abstract

We present the first measurement of the induced proton polarization P_n in pi^0 electroproduction on the proton around the Delta resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W=1231 MeV and Q^2 = 0.126 (GeV/c)^2, respectively. We measured a large induced polarization, P_n = -0.397 +/- 0.055 +/- 0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model.

4 pages, 2 figures

References in corpus (1)

• Meson-exchange Model for $\pi N$ scattering and $\gamma N->\pi N$ reaction

Cited by in corpus (21)

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• Electroexcitation of nucleon resonances
• Study of Non-Strange Baryon Resonances with Meson Photoproduction
• Search for Quadrupole Strength in the Electro-excitation of the Delta(1232)
• Investigation of the conjectured nucleon deformation at low momentum transfer
• Measurement of the recoil polarization in the p (\vec e, e' \vec p) pi^0 reaction at the Δ(1232) resonance
• Recoil Polarization for Delta Excitation in Pion Electroproduction
• 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
• Measurement of the Polarized Structure Function ${\sigma }_{L{T}^{\prime }}$ for $p(\vec{e},e^{\prime }{\pi }^{+})n$ in the $\Delta (1232)$ Resonance Region
• 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
• Measurement of the Transverse-Longitudinal Cross Sections in the p (e,e'p)pi0 Reaction in the Delta Region
• Measurements of the gamma*p->Delta Reaction At Low Q^2: Probing the Mesonic Contribution
• Jülich-Bonn-Washington Model for Pion Electroproduction Multipoles
• Recoil Polarization Measurements for Neutral Pion Electroproduction at Q^2=1 (GeV/c)^2 Near the Delta Resonance
• Deviation of the Nucleon Shape From Spherical Symmetry: Experimental Status
• 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}
• Coupled-channel analysis of pion- and eta-electroproduction with the Jülich-Bonn-Washington model
• $\Delta$(1232) electroproduction amplitudes in chiral soliton models of the nucleon
• Q^2-evolution of nucleon-to-resonance transition form factors in a QCD-inspired vector-meson-dominance model