Summary
We investigate different models for nonleptonic weak hyperon decays, and find that only hard-pion current algebra with the inclusion of decuplet poles and 〈B|H p.v. w |B′〉=0 gives a consistent description for both types of decays, B i →B f π and B i →B fγ. We also show that the resulting strength andd′/f′ ratio of the phenomenological weak spurion (d′/f′=−0.86) are consistent with models which dynamically generate the weak spurion. The pole model and soft current algebra with a nonvanishing parity-violating spurion are also considered but are inconsistent with K s → ππ and the sign and magnitude of the measured Σ+ → pγ asymmetry parameter.
Riassunto
Si indaga su differenti modelli per i decadimenti degli iperoni deboli non leptonici, e si trova che solo l’algebra delle correnti dei pioni duri, con l’inclusione dei poli dei decupletti e 〈B|H p.v. w |B′〉=0, dá una descrizione consistente per entrambi i tipi di decadimenti B i →B f π e B i →B f γ. Si mostra ancora che la forza risultante e il rapportod′/f′ degli spurioni deboli fenomenologici (d′/f′=−0.86) sono consistenti con i modelli che generano dinamicamente gli spurioni deboli. Il modello del polo e l’algebra delle correnti tenere, con una spurione che non sparisce e che viola la parità, sono ancora consistenti, ma sono inconsistenti con K s → ππ e con il segno e la grandezza del parametro misurato dell’asimmetria Σ+→pγ.
Реэюме
Мы исследуем раэличные модели для нелептонных слабых распадов гиперонов и получаем, что только алгебра токов жестких пионов с включением декуплетных полюсов и 〈B|H p.v. w |B′=0 обеспечивает согласованное описание для обоих тупов распадов, B i →B f π и B i →Bfγ. Мы также покаэываем, что реэультируюшая сила иd′/f′ отнощение для феноменологического слабого щпуриона (d′/f′=−0.86) согласуются с моделями, которые динамически генерируют слабый щпурион. Также рассматривается полюсная модель и алгебра мягких токов с неисчеэаюшим щпурионом, нарущаюшим четность, но зтот подход не согласуется с K s →ππ и со энаком и величиной иэмеренного параметра асимметрии Σ+→рγ.
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Gavroglu, K., Scadron, M.D. Models for nonleptonic weak hyperon decays. Nuov Cim A 14, 812–826 (1973). https://doi.org/10.1007/BF02729431
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DOI: https://doi.org/10.1007/BF02729431