Summary
Interference between parity-allowed and parity-forbidden transition amplitudes is considered for the special case of two overlapping resonances having equalJ and opposite π. Parity mixing between states in the continuum is discussed with a modified version of theR-matrix theory. The interference effects of the first order in the parity mixing, which can be observed in polarization experiments, are calculated for the (\(\vec p\), α) reaction. The specific case of the 13 482 keV level in20Ne is discussed in detail.
Riassunto
Si considera l’interferenza tra ampiezze di transizione permesse e proibite dalla conservazione della parità, per il caso di due risonanze sovrapposte aventi lo stessoJ e parità opposta. Il mescolamento di parità fra stati nel continuo viene analizzato con una versione modificata della teoria della matriceR. Sono calcolati, per la reazione (\(\vec p\), α), gli effetti di interferenza al primo ordine nel mescolamento di parità, che possono essere osservati in esperimenti di polarizzazione. Si discute infine in dettaglio il caso del livello a 13482 keV in20Ne.
Реэюме
Рассматривается интерференция между амплитудами раэрещенных и эапрешенных по четности переходов для специального случая двух перекрываюшихся реэонансов, имеюших равныеJ и противоположные π. Обсуждается смещивание четности между состояниями в континууме в случае модифицированного варианта теории R-матрицы. Для (\(\vec p\) а) реакции вычисляются интерференционные зффекты первого порядка при смещивании четности, которые могут наблюдаться в поляриэационных зкспериментах. Подробно обсуждается специальный случай уровня 13 482 кзВ в20Ne.
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Interferences with underlying levels withJ ≠ 1, although possibly troublesome, can be distinguished from the effect shown in eq. (6) due to the different symmetry character of their angular dependence. Another level withJ=1− could possibly exist at 13.52 MeV, but its identification is still uncertain (13).
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Bizzeti, P.G., Maurenzig, P.R. First-order parity-violating effects from two-resonance interference in (\(\vec p\), α) reactions, α) reactions. Nuov Cim A 56, 492–501 (1980). https://doi.org/10.1007/BF02732099
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DOI: https://doi.org/10.1007/BF02732099