Summary
It is shown that Walecka’s version of the Goldhaber-Teller model of the «giant dipole» nuclear collective oscillations, generalized to spin-isospin vibrational modes by the author, may be used to describe the gross features of the inelastic electron scattering results in a semi-quantitative manner. We have obtained simple expressions for the longitudinal and transverse matrix elements leading to electric dipole (1−) and magnetic quadrupole (2−) collective states in12C and16O. The decay widths of these states were calculated also, using Wigners.R-matrix theory, and are generally in good agreement with the observed widths.
Riassunto
Si mostra che la versione di Walecka del modello di Goldhaber-Teller delle oscillazioni mzcleari collettive di «dipolo giganteα, generalizzata dall’autore ai modi vibrazionali spin-isospin, può essere usata per descrivere in modo semiquantitativo le caratteristiche grossolane dei risultati dello scattering elettronico anelastico. Si sono ottenute semplici espressioni degli elementi di matrice longitudinale e trasversale che portano a stati collettivi di dipole elettrico (1−) e quadrivpolo magnetico (2−) nel12C e nel16O. Si sono calcolate anche le ampiezze di decadimento di questi stati, con la teoria della matriceR di Wigner, ed esse sono generalmente in buon accordo con quelle osservate.
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References
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Überall, H. The giant resonance in inelastic electron scattering. Nuovo Cimento B (1965-1970) 41, 25–36 (1966). https://doi.org/10.1007/BF02711112
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DOI: https://doi.org/10.1007/BF02711112