Differential Cross Section for Coherent Photon Scattering from<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">He</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>4</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math>at 180 MeV

Ej, Austin; Booth, E. T.; Ek, McIntyre; Jp, Miller; Bl, Roberts; Da, Whitehouse; Dodson, G.

doi:10.1103/physrevlett.57.972

Cited by 24 publications

(9 citation statements)

References 8 publications

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“…6.3 below. As was already found in the very first measurements at Bates (MIT) [20,23], any version of the ∆-hole model -the original version of Ref. [107], a simplified version [109] based on a local-density approximation, and a version [108] corrected [46] for the seagull contributions to the elementary γN scattering amplitude -fails to explain the large size of the differential cross section observed at angles θ LAB > ∼ 90 • .…”

Section: Compton Scattering By 4 He In the ∆ Rangementioning

confidence: 89%

“…However, all the considered models fail to correctly describe the experimental results at large angles, where the 4 He data [20,23,29,45,46] largely exceed the predictions. Comparing the different calculations, one may conclude that the density-dependent self-energy of the ∆ which results in a shift and broadening of the ∆ peak is not the only effect which has to be taken into account to explain nuclear Compton scattering in the ∆ range.…”

Section: Missing Effects At Large Angles -Nonlocalitymentioning

confidence: 97%

“…One reason for this delay is that only a very fragmentary set of data was available, even for the nucleus 4 He which was the subject of principal interest for experimental researches [20,23,29,35,40,44,45]. On the experimental side considerable progress has been made very recently by the Göttingen-Mainz collaboration at MAMI (Mainz) [44,46] and by the LEGS collaboration at Brookhaven [45] where differential cross sections for Compton scattering by 4 He have been measured in large angular and energy intervals.…”

Section: Motivations For Studying Nuclear Compton Scatteringmentioning

confidence: 99%

“…Furthermore, the first excited state is at 20 MeV, thus making the separation of elastic and inelastic processes easy. Previous experiments on Compton scattering by 4 He in the ∆ range [20,23,29,35,40] were carried out using the bremsstrahlung method and, therefore, may have suffered from the wellknown systematic errors contained in that method. In spite of that, the use of large NaI(Tl) detectors made it possible to get good data on the elastic reaction at energies close to the end points of the bremsstrahlung beams.…”

Section: Compton Scattering By 4 He In the ∆ Rangementioning

confidence: 99%

“…and 20) with the hermitian conjugate to be added in both cases. Here S and T are the 1/2-to-3/2 transition operators in spin space and isospin space, respectively.…”

Section: Corrections To the Correlation Functionmentioning

confidence: 99%

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Compton scattering by nuclei

et al. 2000

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The concept of Compton scattering by even-even nuclei from giant-resonance to nucleon-resonance energies and the status of experimental and theoretical researches in this field are outlined. The description of Compton scattering by nuclei starts from different complementary approaches, namely from second-order S-matrix and from dispersion theories. Making use of these, it is possible to incorporate into the predicted nuclear scattering amplitudes all the information available from other channels, viz. photon-nucleon and photon-meson channels, and to efficiently make use of models of the nucleon, the nucleus and the nucleon-nucleon interaction. The total photoabsorption cross section constrains the nuclear scattering amplitude in the forward direction. The specific information obtained from Compton scattering therefore stems from the angular dependence of the nuclear scattering amplitude, providing detailed insight into the dynamics of the nuclear and nucleon degrees of freedom and into the interplay between them. Nuclear Compton scattering in the giant-resonance energy-region provides information on the dynamical properties of the in-medium mass of the nucleon. Most prominently, the electromagnetic polarizabilities of the nucleon in the nuclear medium can be extracted from nuclear Compton scattering data obtained in the quasideuteron energy-region. In our description of this latter process special emphasis is laid upon the exploration of many-body and two-body effects entering into the nuclear dynamics. Recent results are presented for two-body effects due to the mesonic seagull amplitude and due to the excitation of nucleon internal degrees of freedom accompanied by meson exchanges. Due to these studies the inmedium electromagnetic polarizabilities are by now well understood, whereas the understanding of nuclear Compton scattering in the ∆-resonance range is only at the beginning. Furthermore, phenomenological methods how to include retardation effects in the scattering amplitude are discussed and compared with model predictions.

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Section: Compton Scattering By 4 He In the ∆ Rangementioning

confidence: 89%

Section: Missing Effects At Large Angles -Nonlocalitymentioning

confidence: 97%

Section: Motivations For Studying Nuclear Compton Scatteringmentioning

confidence: 99%

Section: Compton Scattering By 4 He In the ∆ Rangementioning

confidence: 99%

“…and 20) with the hermitian conjugate to be added in both cases. Here S and T are the 1/2-to-3/2 transition operators in spin space and isospin space, respectively.…”

Section: Corrections To the Correlation Functionmentioning

confidence: 99%

See 3 more Smart Citations