First Measurement of the Absolute Branching Fraction of Lambda -> p mu(-)(nu)over-bar(mu)
First Measurement of the Absolute Branching Fraction of Lambda -> p mu(-)(nu)over-bar(mu)
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首次测量 Lambda 的绝对分支分数 -> p mu(-)(nu)over-bar(mu)
DOI：
10.1103/physrevlett.127.121802
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发表时间：
2021
影响因子：
8.6
通讯作者：
Briere R.
中科院分区：
文献类型：
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作者：
Ablikim M.;Achasov M. N.;Adlarson P.;Ahmed S.;Albrecht M.;Aliberti R.;Amoroso A.;An M. R.;An Q.;Bai X. H.;Bai Y.;Bakina O.;Ferroli R. Baldini;Balossino I;Ban Y.;Begzsuren K.;Berger N.;Bertani M.;Bettoni D.;Bianchi F.;Bloms J.;Bortone A.;Boyko I;Briere R.
本文首次报道了用BESIII探测器收集的湮灭样品的绝对分支分数。分支分数B（Λ→pμ-ν <$μ）=[1.48±0.21（stat）±0.08（syst）]×10 ~（-4），比间接测量精度提高了30%左右。将这一结果与世界平均值相结合，我们得到的比值为，这与标准模型假设轻子味普适性的预言相一致。的分支分数的不对称性和也被确定，并没有发现违反的证据。
The absolute branching fraction ofis reported for the first time based on anannihilation sample ofevents collected with the BESIII detector at. The branching fraction is determined to be B(Λ→pμ-ν¯μ)=[1.48±0.21(stat)±0.08(syst)]×10-4, which is improved by about 30% in precision over the previous indirect measurements. Combining this result with the world average of, we obtain the ratioto be, which agrees with the standard model prediction assuming lepton flavor universality. The asymmetry of the branching fractions ofandis also determined, and no evidence forviolation is found.