0000000000191386
AUTHOR
R. Kondratjev
Compton scattering from the free and bound proton at backward angles above π-threshold
Differential cross sections for Compton scattering from the free proton at Theta(gamma)(lab) = 130.7 degrees in the energy region from 200 MeV to 410 MeV and far quasi-free Compton scattering from the proton bound in the deuteron at Theta(gamma)(lab) = 148.8 degrees in the energy region from 200 MeV to 290 MeV have been measured. The free proton data are in agreement with dispersion-theory predictions based on standard parameters. The difference of the proton polarizabilities has been extracted from the quasi-free data. Our result, - = [9.1 +/- 1.7(stat + syst) +/- 1.2(mod)] x 10(-4) fm(3), is in reasonable agreement with the world average of the free proton data if the backward spin polari…
Compton scattering by the proton through θcms = 75° and 90° in the Δ-resonance region
Abstract Differential cross sections for Compton scattering by the proton have been measured in the energy interval between 200 and 500 MeV at scattering angles of θcms = 75° and θcms = 90° using the CATS, the CATS/TRAJAN, and the COPP setups with the Glasgow Tagger at MAMI (Mainz). The data are compared with predictions from dispersion theory using photo-meson amplitudes from the recent VPI solution SM95. The experiment and the theoretical procedure are described in detail. It is found that the experiment and predictions are in agreement as far as the energy dependence of the differential cross sections in the Δ-range is concerned. However, there is evidence that a scaling down of the reso…
A high angular-resolution and time-of-flight detector system for recoil protons from the reactions p(γ, γ)p and p(γ, π0)p
Using the Mainz NaI(Tl)BaF2 photon spectrometer CATS (Compton And Two photon Spectrometer) together with the prototype of a universal spectrometer for recoil protons TRAJAN (TRAjectory ANalyser) we have studied different methods to disentangle Compton scattering by the proton from the large π0 background through the energy range of the Δ resonance. CATS is a modular 48 cm ⊘ × 64 cm NaI(Tl) detector with an energy resolution of 1.5% combined with a 2π array of 61 BaF2 detectors. TRAJAN consists of a hodoscope with two planes, a wire chamber with horizontal and vertical wires and a grid of horizontal and vertical plastic scintillator strips, followed by a wall of nine NaI(Tl) detectors. By t…
Elastic and inelastic photon scattering from 12C
Abstract The elastic and inelastic photon scattering from 12 C was investigated in the energy range of the Δ-resonance ( E γ = 200–500 MeV) at a scattering angle of 40°. The experiment was performed with the tagged photon facility at the cw electron accelerator MAMI ( E e − = 855 MeV). By using a large NaI(Tl) detector having an energy resolution of 1.5%, the elastic scattering could be separated from the inelastic process to the first excited state ( E x = 4.44 MeV of 12 C. The differential cross section for the coherent scattering is compared with a simple static ansatz, that uses the known charge form factor, and with a recent Δ-hole calculation.
Compton scattering from the free and bound proton above π-threshold
The differential cross sections for Compton scattering from the proton have been measured at MAMI with three different detector setups. There is a good agreement among all the results. The theoretical calculation based on dispersion relations shows that there is no drastic change necessary in the parameters of this approach.
"Table 1" of "Compton scattering from the free and bound proton at backward angles above pi threshold."
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