Summary
We suggest that nuclear Compton scattering below meson production threshold can provide a fundamental tool in the analysis of the exchange effects in nuclei. We evaluate exchange terms and show that they strongly affect the diffractive behaviour even in the low-momentum-transfer region.
Riassunto
Si suggerisce la diffusione Compton su nuclei sotto la soglia di produzione del pione come uno strumento fondamentale nell’analisi degli effetti di scambio nei nuclei. Si valutano i termini di scambio e si mostra che essi ne influenzano fortemente il comportamento diffrattivo anche a basso momento trasferito.
Реэюме
Мы предполагаем, что комптоновское рассеяние ядер ниже порога обраэования меэонов может служить инструментом при аналиэе обменных эффестов в ядрах. Мы вычисляем обменные члены и покаэываем, что они сильно влияют на дифракционное поведение даже в области малых передавемых импульсов.
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References
For a general review see,e.g.,A. M. Green:Rep. Prog. Phys.,39, 1109 (1976).
P. Christillin andM. Rosa-Clot:Phys. Lett.,51 B, 125 (1974).
P. Christillin andM. Rosa-Clot:Nuovo Cimento,28 A, 29 (1975).
P. Christillin andM. Rosa-Clot:Nuovo Cimento,32 A, 217 (1976).
R. G. Sachs andN. Austern:Phys. Rev.,81, 705 (1950).
V. I. Goldansky, O. A. Karpukhin, A. V. Kutsenko andV. V. Pavlovskaya:Nucl. Phys.,18, 473 (1960).
J. Ahrens, H. Borchert, K. H. Czock, H. B. Eppler, H. Gimm, H. Gundrum, M. Kröning, P. Riehn, G. Sita Ram, A. Zieger andB. Ziegler:Nucl. Phys.,251 A, 479 (1975).
It is quite clear from the foregoing arguments that we have neglected the effect of Δ excitation. Since it is known that its threshold is above 150 MeV (as also shown by nuclear experimental data (7) in the cases in which they are available up to 200 MeV), this seems to be a reasonable approximation.
Using the optical theorem and the parametrization for the data of ref. (7) above 50 MeV σA(ω)=288(NZ/A)ω−3/2 mb (B. Ziegler: Internal Note (19.3.1976)), we find Imf(ω) ⋍Z. 12Z/√ω mb·MeV. This amounts to a correction of (5 ÷ 10)% in the elastic Compton-scattering cross-section.
In eq. (3) the possibility of a quadrupole structure of the pion distribution, arising in deformed nuclei because of anisotropy of exchange effects (4), has been overlooked.
M. Chemtob andA. Lumbroso:Nucl. Phys.,17 B, 401 (1970).
M. Gell-Mann, M. L. Goldberger andW. Thirring:Phys. Rev.,95, 1512 (1954).
P. Papatzacos andK. Mork:Phys. Rep.,21 C, 82 (1975).
G. E. Pugh, R. Gomez, D. H. Frisch andG. S. Janes:Phys. Rev.,105, 982 (1957).
R. Caloi, S. Frullani, G. Matone, P. Picozza, D. Prosperi, C. Schaerf, C. Strangio andA. Tranquilli: preprint LNF-76/31(R) (1976).
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Christillin, P., Rosa-Clot, M. Exchange effects in the diffractive behaviour of nuclear Compton scattering. Nuov Cim A 43, 172–180 (1978). https://doi.org/10.1007/BF02734193
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DOI: https://doi.org/10.1007/BF02734193