Summary
From a set of lowest-order quark-loop diagrams for static mesic amplitudes involving vector and axial vector vertices, we determine the effective quark mass and the meson-quark-quark coupling constants for three types of quark models. These parameters are applied to evaluate certain mesic decays and theSU 3 mass splitting of the 0− octet and 1− nonet, which serve as tests for the quark models. Adler’s low-energy theorem for the π0 → 2γ decay is derived in our approach without invoking the Adler-Schwinger anomaly. The test favors the Nambu-Han model of integrally charged quarks. Critical examinations of the underlying assumption of the quark-loop dominance are made, and a speculation on a physical model which allows such a situation will be proposed.
Riassunto
Da una classe di diagrammi di anse di quark di minimo ordine per ampiezze mesoniche statiche che coinvolgono vertici vettoriali e vettoriali assiali, si determina la massa effettiva dei quark e le costanti di accoppiamento mesone-quark-quark per tre tipi di modelli a quark. Si applicano questi parametri per valutare alcuni decadimenti mesonici e la separazione di massa diSU 3 dell’ottetto 0− e del nonetto 1−, che servono di controlli per il modello a quark. Si deduce nel nostro approccio il teorema di bassa energia di Adler per il decadimento π0 → 2γ senza ricorrere all’anomalia di Adler-Schwinger. Il controllo favorisce il modello di Nambu-Han di quark a carica intera. Si eseguono esami critici delle ipotesi che stanno alla base del predominio delle anse di quark, e si propone di riflettere su un modello fisico che consente una tale situazione.
Реэюме
Исходя иэ системы кварковых петельных диаграмм для статических меэонных амплитуд, включаюших векторные и аксиально-векторные верщины, мы определяем зффективную массу кварка и константу свяэи меэон-кварк-кварк для трех типов кварковых моделей. Эти параметры применяются для вычисления некоторых меэонных распадов иSU 3 расшепления масс для октета 0− и нонета 1−, которые служат для проверки кварковых моделей. В нащем подходе беэ испольэования аномалии Адлера-Щвингера, выводится теорема Адлера при ниэких знергиях для распада π0 → 2γ. Проверка отдает предпочтение модели Намбу-Гана для кварков с целочисленным эарядом. Проводятся критические исследования основного предположения о доминантности кварковых петель. Обсуждается фиэическая модель, которая допускает такую ситуацию.
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Work assisted in part by the U.S. Atomic Energy Commission.
Work performed at Ames Laboratory of the U.S. Atomic Energy Commission.
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Suura, H., Young, BL. Quark-loop dynamics and meson decays. Nuov Cim A 11, 101–120 (1972). https://doi.org/10.1007/BF02722781
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DOI: https://doi.org/10.1007/BF02722781