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Quenching of $1^+$ excitations in the double giant resonance

C. A. Bertulani·V. Yu. Ponomarev·V. V. Voronov
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Abstract

The electromagnetic excitation of the two-phonon isovector giant dipole resonance in relativistic projectiles incident on heavy targets can be proceed via several intermediate $1^-$ one-phonon giant resonance states. In two step electric dipole transitions the population of $0^+$, $1^+$, and $2^+ $ two-phonon states are possible. We calculate the amplitude distribution of $1^-$ excitations with an RPA formalism, and use it to calculate the electromagnetic excitation of two-phonon states in second order perturbation theory and coupled-channels. We show that a conspiracy between angular momentum coupling and the strength of the electromagnetic fields suppresses contributions of $1^+$ states to the total cross sections.

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C. A. Bertulani, V. Yu. Ponomarev, V. V. Voronov. 1996-06-04. Quenching of $1^+$ excitations in the double giant resonance. https://doi.org/10.1016/s0370-2693(96)01204-x

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