Measurement of higher-order multipole amplitudes in psi(3686) -> gamma chi(c1,2) with chi(c1,2) -> gamma J/psi and search for the transition eta(c)(2S) -> gamma J/psi
Measurement of higher-order multipole amplitudes in psi(3686) -> gamma chi(c1,2) with chi(c1,2) -> gamma J/psi and search for the transition eta(c)(2S) -> gamma J/psi
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使用 chi(c1,2) -> gamma J/psi 测量 psi(3686) -> gamma chi(c1,2) 中的高阶多极振幅并搜索转变 eta(c)(2S) -> gamma J
DOI：
10.1103/physrevd.95.072004
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发表时间：
2017
影响因子：
5
通讯作者：
Caki
中科院分区：
文献类型：
--
作者：
Ablikim M.;Achasov M. N.;Ai X. C.;Albayrak O.;Albrecht M.;Ambrose D. J.;Amoroso A.;An F. F.;An Q.;Bai J. Z.;Ferroli R. Baldini;Ban Y.;Bennett D. W.;Bennett J. V.;Bertani M.;Bettoni D.;Bian J. M.;Bianchi F.;Boger E.;Boyko I.;Briere R. A.;Cai H.;Cai X.;Caki
使用 BESIII 探测器收集的 106 个事件，我们测量了超过主要电偶极子振幅的衰减的多极振幅。确定了归一化磁四极（M2）振幅和归一化电八极振幅。发现 M2 振幅与零显着不同，并且与理论预测一致。我们还得到了 M2 的贡献率和衰减率，这与理论预期非常吻合。通过考虑多极贡献，我们测量级联衰减的产物分支分数并搜索过程。的产物支化分数大于公布的测量结果，而 的结果是一致的。没有观察到明显的衰减信号，并且确定了 90% 置信水平下的产物支化分数的上限。
Using 106events collected with the BESIII detector, we measure multipole amplitudes for the decaybeyond the dominant electric-dipole amplitudes. The normalized magnetic-quadrupole (M2) amplitude forand the normalized electric-octupole amplitudes for,are determined. The M2 amplitudes forandare found to differ significantly from zero and are consistent with theoretical predictions. We also obtain the ratios of M2 contributions ofanddecays to,and, which agree well with theoretical expectations. By considering the multipole contributions of, we measure the product branching fractions for the cascade decaysand search for the processthrough. The product branching fraction forislarger than published measurements, while those ofare consistent. No significant signal for the decayis observed, and the upper limit of the product branching fraction at the 90% confidence level is determined.