Compton scattering from C12 using tagged photons in the energy range 65–115 MeV (original) (raw)
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A study of proton scattering on 12C and 13C at 7 MeV
Nuclear Physics A, 1969
Differential cross sections and polarizations of proton scattering on 12C and 18C have been measured at Ep = 7 MeV. Total x2C +p and ~aC +p reaction cross sections have been estimated. Optical model analyses indicate that the elastic scattering data cannot be satisfactorily described by averaged parameters. The deduced optical parameters have been used in some DWBA calculations. NUCLEAR REACTIONS x2,1aC(p, p), lsC(p, d); E = 7 MeV; measured tr(Ep, 0), E P(0); deduced optical parameters; natural and enriched targets.
Abstract Compton Scattering by the Nucleon ⋆
2004
The status of Compton scattering by the nucleon at energies of the first and second resonance is summarized. In addition to a general test of dispersion theories and a precise determination of polarizabilities, the validities of four fundamental sum rules are explored. Recommended averages of experimental values for the electromagnetic polarizabilities and spin-polarizabilities of the nucleon are determined: αp = 12.0 ± 0.6, βp = 1.9 ∓ 0.6, αn = 12.5 ± 1.7, βn = 2.7 ∓ 1.8 (unit 10 −4 fm 3), γ (p) π = −38.7 ± 1.8, γ (n) π = 58.6 ± 4.0 (unit 10 −4 fm 4).
Compton scattering of polarized γ rays by O16 for Eγ=25–40MeV
Physical Review C, 2004
Measurements of the polarization asymmetries ⌺͑ c.m. ͒ and ⌺͑E ␥ ͒ of Compton scattering by 16 O have been performed in the energy range of 25-40 MeV over a range of scattering angles between 90 and 150°. An analysis of the present data combined with previous results indicates that significant, narrow concentrations of E2 strength are not present below an excitation energy of 40 MeV. The existence, however, of a broad isovector giant quadrupole resonance exhausting a large percentage of the isovector energy weighted sum rule is not ruled out by the combined data. Additionally, the present data are insensitive to modifications to the free values of the nucleon polarizabilities, but cannot rule them out.
Radiation Physics and Chemistry, 2010
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Compton scattering by the nucleon
Radiation Physics and Chemistry, 2006
The status of Compton scattering by the nucleon at energies of the first and second resonance is summarized. In addition to a general test of dispersion theories and a precise determination of polarizabilities, the validities of four fundamental sum rules are explored. Recommended averages of experimental values for the electromagnetic polarizabilities and spin-polarizabilities of the nucleon are determined: αp = 12.0 ± 0.6, βp = 1.9 ∓ 0.6, αn = 12.5 ± 1.7, βn = 2.7 ∓ 1.8 (unit 10 −4 fm 3), γ (p) π = −38.7 ± 1.8, γ (n) π = 58.6 ± 4.0 (unit 10 −4 fm 4).
Compton scattering from the proton
Physical Review C, 1993
The proton Compton effect has been studied in the region between the threshold for pion photoproduction and the A(1232). The measurements were performed using bremmstrahlung from the high duty-factor electron beam available at the Saskatchewan Accelerator Laboratory. Elastically scattered photons were detected with an energy resolution of approximately 1.5%%uo using a large NaI total absorption scintillation detector. Differential cross sections were measured for photon energies in the range 136 MeV~E~~289 MeV and for angles in the range 25'& 0&,b & 135'. The angular distributions and the excitation functions derived from these data are in agreement with recent theoretical analyses. The results were interpreted within a formalism based in part on dispersion relations to obtain modeldependent estimates of the electric and magnetic polarizabilities, a and P. We find, subject to the dispersion sum rule constraint a+P= (14.2+0. 5) X 10 fm' that a =(9.8+0.4+1.1)X 10 fm' and P=(4.4+0.4+ 1. 1)X 10 fm', which are consistent with the best previous measurements.
Physics Reports, 2000
The role of Compton scattering in investigations of the degrees of freedom of the nucleus 3 Compton scattering below pion threshold: general aspects 3.1 The photon-nucleus scattering amplitude in second-order perturbation theory. .. .. 3.2 The nonrelativistic photon-nucleus interaction and the concept of currents. .. .. . .
Compton scattering by the proton
Physics Letters B, 2001
Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < ∼ E γ < ∼ 800 MeV and photon scattering angles 30 • < ∼ θ lab γ < ∼ 150 • , using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The data are in good agreement with the dispersion theory based on the SAID-SM99K parameterization of photo-meson amplitudes. From the subset of data between 280 and 360 MeV the resonance pion-photoproduction amplitudes were evaluated leading to the multipole E2/M1 ratio EMR(340 MeV) = (−1.6 ± 0.4 stat+syst ± 0.2 model )%. From all data below 455 MeV the proton's backward spin polarizability was determined to be γ π = (−37.9 ± 0.6 stat+syst ± 3.5 model ) × 10 −4 fm 4 .
Analysis of 12 C + 12 C Elastic Scattering for Energy between 70 and 1440 MeV
In the present work, we reanalysis the 12 C + 12 C refractive scattering over a wide energy range. The analysis is performed in the framework of optical model with the solution of the non-relativistic Schr¨odinger equation. For the real part of the optical model potential, we used real folded potentials based on JLM effective nucleon-nucleon (N N) interaction. For the imaginary part we used the familiar and conventional Woods-Saxon (WS) form with three adjusted parameters. Different local density approximations (LDA) are used for JLM effective N N interaction. Our main purpose is to find a systematic optical model potential over a wide energy range between 70.7 and 1440 MeV. The real JLM folded potentials with a shallow WS imaginary potentials successfully and systematically reproduced the general feature of the refractive elastic scattering of 12 C + 12 C. The energy dependence of the real (J R) and imaginary (J I) volume integrals and reaction cross sections σ R is investigated.