Measurement of the generalized polarizabilities of the proton in virtual Compton scattering at Q2=0.92 and 1.76 GeV2

We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=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 piN intermediate states.     

Anomaly in the p-d bremsstrahlung near the break-up threshold

Measurements of p-d bremsstrahlung cross sections performed by detecting the outgoing particles in coincidence at 20°-20° in the laboratory system, show a marked energy dependence near the break-up threshold, at variance with the behaviour far from it as seen from other experiments.     

The\overrightarrow p - Si elastic scattering in the region of giant multipole resonances

Analyzing powers and cross sections for the scattering of polarized protons from Si have been measured at eight energies between 17 and 29MeV. The analysing powers show an “anomalous” behaviour and an optical model analysis yields a non-monotonic effect in the spin-orbit potential.     

On the radial distribution of the 1f72 proton orbit

Cross sections for magnetic elastic electron scattering of high multipolarity from ⁵¹V and ⁵⁹Co have been measured. They are interpreted in terms of the rms radius of the $\text{1f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ proton orbit. The results for ⁵¹V and ⁵⁹Co 1f_{$\text{7}\text{2}$} rms radii are smaller by 3% and 9%, respectively, than predicted by the Hartree-Fock-Bogoliubov theory.