共查询到8条相似文献,搜索用时 4 毫秒
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利用北京谱仪采集的1400万Ψ′数据,对粲偶素衰变到赝标介子对KSKL进行了寻找,首次观测到信号并测量了其衰变分支比,并首次确定Ψ′衰变中强振幅和电磁振幅之间的相角接近±90°.结合从北京谱仪采集的J/Ψ数据中测得的J/Ψ→KSKL的分支比,确定了Ψ′→KSKL相对于微扰量子色动力学“12%”规则的反常增强,对粲偶素的衰变机制研究提出了新的挑战. 相似文献
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PINGRong-Gang JIANGHuan-Qing 《理论物理通讯》2003,40(2):183-187
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文章介绍2001年度国家自然科学奖二等奖获奖成果,在北京正负电子对撞机上采集了Ψ(2S)粒子大数据样本,开展了粲偶素物理的广泛研究:完成了6个粲偶素涉及质量,宽度和衰变化支比等大批重要参数的首次测量或高精度测量;通过对Ψ(2S)和J/Ψ强衰变性质的比较研究,观察到一系列反常现象,挑战现有理论图像。该项研究成果对量子色动力学的检验与发展具有重要意义,为我国粲偶素物理实验研究的继续发展并保持先进水平奠定坚实基础。 相似文献
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In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (i) The leading order pQCD predictions for the branching ratio Br(B^+→K^+K0^*(1430)^0)are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^*(1430)K decay modes are also presented and will be tested by the LHC experiments; (ii) The annihilation contributions play an important role in these considered decays, for B^0→K0^*(1430)^±K^± decays,for example,which are found to be (1-4)×10^-6. 相似文献
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Based on the assumption of a two-quark structure of the scalar meson f0(980) ,we calculate the branching ratios and CP-violating asymmetries for the four B → f0(980) π and B → f0(980) η^(') decays by employing the perturbative QCD(pQCD) factorization approach. The leading order pQCD predictions for branching ratios are,Br(B^-→ f0(980) π^-) ~ 2.5×10^-6,Br(Bˉ^0 → f0(980) π^0) ~ 2.6×10^-7,Br(Bˉ^0 → f0(980) η) ~ 2.5×10^-7 and Br(Bˉ^0 → f0(980) η ) ~ 6.7×10^-7,which are consistent with both the QCD factorization predictions and the experimental upper limits. 相似文献