分类: 物理学 >> 核物理学 提交时间: 2016-09-12
摘要: We report a measurement of the B0→ψ(2S)π0 branching fraction based on the full Υ(4S) data set of 772×106 BB¯ pairs collected by the Belle detector at the KEKB asymmetric-energy e+e− collider. We obtain B(B0→ψ(2S)π0)=(1.17±0.17(stat)±0.08(syst))×10−5. The result has a significance of 7.2 standard deviations and is the first observation of the decay B0→ψ(2S)π0.