We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions PLL-PTT/ϵ and PLT, and the electric and magnetic generalized polarizabilities (GPs) αE(Q2) and βM(Q2) at momentum transfer Q2=0.92 and 1.76  GeV2. The electric GP shows a strong falloff with Q2, 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 Q2, compensated at higher Q2 by a paramagnetic contribution from πN intermediate states.

Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q**2=0.92 and 1.76 GeV**2

Pasquini B.;
2004-01-01

Abstract

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions PLL-PTT/ϵ and PLT, and the electric and magnetic generalized polarizabilities (GPs) αE(Q2) and βM(Q2) at momentum transfer Q2=0.92 and 1.76  GeV2. The electric GP shows a strong falloff with Q2, 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 Q2, compensated at higher Q2 by a paramagnetic contribution from πN intermediate states.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11571/115684
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