Measurement of the Generalized Polarizabilities of the Proton in Virtual Compton Scattering at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>=</mml:mo><mml:mn>0.92</mml:mn></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>1.76</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:msup><mml:mrow><mml:mi mathvariant="normal">G</mml:mi><mml:mi mathvariant="normal">e</mml:mi><mml:mi mathvariant="normal">V</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msup></mml:math>

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions ${P}_{LL}\ensuremath{-}{P}_{TT}/ϵ$ and ${P}_{LT}$, and the electric and magnetic generalized polarizabilities (GPs) ${\ensuremath{\alpha}}_{E}({Q}^{2})$ and ${\ensuremath{\beta}}_{M}({Q}^{2})$ at momentum transfer ${Q}^{2}=0.92$ and $1.76\text{ }\text{ }{\mathrm{G}\mathrm{e}\mathrm{V}}^{2}$. The electric GP shows a strong falloff with ${Q}^{2}$, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low ${Q}^{2}$, compensated at higher ${Q}^{2}$ by a paramagnetic contribution from $\ensuremath{\pi}N$ intermediate states.

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