Summary
We made a direct measurement of the π0 weak decay branching ratio of the 12Λ C hypernucleus for the first time. The branching ratio is estimated to beΓ π 0/Γ=0.166±0.055 from the measurement. The branching ratio agrees fairly with a theoretical calculation with a realistic pion distorted wave function, but is inconsistent with a calculation with a free π0 wave function. An upper limit of the π0 decay branching ratio of the 11Λ B hypernucleus was also estimated to beΓ π 0/Γ<0.291 (90% confidence level).
Riassunto
È stata misurata direttamente la frazione di decadimento (debole) dell’ipernucleo 12Λ C in π0 per la prima volta. Dalla misura risulta cheΓ π 0/Γ=0.166±0.055. Il rapporto coincide con il calcolo teorico con una funzione d’onda distorta realistica pionica, ma non è in accordo con il calcolo con la funzione d’onda libera del pione. Anche il limite superiore stimato del rapporto di decadimento pionico dell’ipernucleo 11Λ B èΓ π 0/Γ<0.291 (livello di confidenza 90%).
Реэюме
Впервые проводится прямое иэмерение отнощение ветвей π0 слабого распада гиперядер 12Λ C. Иэ иэмерения оценивается отнощение ветвей, которое составляетΓ π 0/Γ=0.166±0.055. Отнощение ветвей совпадает с теоретическим расчетом, испольэуюшим искаженную волновую функцию реального пиона, но не согласуется с вычислением для волновой функции свободного π0. Также оценивается верхний предел отнощения ветвей π0 распада гиперядра 11Λ B, который составляетΓ π 0/Γ<0.291 (с достоверностью 95%).
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Work supported by Bundesministerium für Forschung und Technologie.
Work supported by the Grant-in-Aid Encouragement of Young Scientists of the Japan Ministry of Education, Science and Culture.
This work is partially supported by the Grant-in-Aid for Special Project Research on Meson Science of the Japan Ministry of Education, Science and Culture.
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Sakaguchi, A., Brückner, W., Paul, S. et al. A measurement of the π0 decay of 12Λ C and 11Λ B hypernucleihypernuclei. Nuov Cim A 102, 511–519 (1989). https://doi.org/10.1007/BF02734870
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DOI: https://doi.org/10.1007/BF02734870