Measurement of the Beam-Recoil Polarization in Low-Energy Virtual Compton Scattering from the Proton

Abstract

Double-polarization observables in the reaction $\vec{e}p\to e^{\prime }\overrightarrow{p^{\prime }}\gamma$ have been measured at $Q^2=0.33(GeV/c{)}^2$. The experiment was performed at the spectrometer setup of the A1 Collaboration using the 855 MeV polarized electron beam provided by the Mainz Microtron (MAMI) and a recoil proton polarimeter. From the double-polarization observables the structure function $P_{LT}^{\perp }$ is extracted for the first time, with the value $(-15.4\pm 3.3(stat.{)}_{-2.4}^{+1.5}(syst.))Ge{V}^{-2}$, using the low-energy theorem for Virtual Compton Sattering. This structure function provides a hitherto unmeasured linear combination of the generalized polarizabilities of the proton.

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Cited by in corpus (8)

• Dispersion Theory in Electromagnetic Interactions
• Spin-dependent sum rules connecting real and virtual Compton scattering verified
• New Insight in the $Q^2$-Dependence of Proton Generalized Polarizabilities
• Measurement of the Generalized Polarizabilities of the Proton at Intermediate $Q^2$
• Virtual Compton scattering at low energies with a positron beam
• Polar polarization: a new method for polarimetry analysis
• The Proton Electromagnetic Generalized Polarizabilities
• Non-forward radiative corrections to electron-carbon scattering