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arXiv · 1209.5217

Isospin Symmetry violation in mirror E1 transitions: Coherent contributions from the Giant Isovector Monopole Resonance in 67As - 67Se

P. G. Bizzeti·G. de Angelis·S. M. Lenzi·R. Orlandi
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Abstract

The assumption of an exact isospin symmetry would imply equal strengths for mirror E1 transitions (at least, in the long-wavelength limit). Actually, large violations of this symmetry rule have been indicated by a number of experimental results, the last of which is the 67As - 67Se doublet investigated at GAMMASPHERE. Here, we examine in detail various possible origins of the observed asymmetry. The coherent effect of Coulomb-induced mixing with the high-lying Giant Isovector Monopole Resonance is proposed as the most probable process to produce a large asymmetry in the E1 transitions, with comparatively small effect on the other properties of the parent and daughter levels.

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P. G. Bizzeti, G. de Angelis, S. M. Lenzi, R. Orlandi. 2012-09-24. Isospin Symmetry violation in mirror E1 transitions: Coherent contributions from the Giant Isovector Monopole Resonance in 67As - 67Se. https://doi.org/10.1103/physrevc.86.044311

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