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arXiv 1507.07692hep-phhep-ex
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半轻子$D_s/B_s$衰变为$π^+π^-$的手征动力学和S波贡献

Chiral Dynamics and S-wave contributions in Semileptonic $D_s/B_s$ decays into $π^+π^-$

Yu-Ji Shi, Wei Wang

摘要:

本文研究了$π^+π^-$系统在$0.5$ - $1.3$ GeV范围内具有不变质量的运动学区域中的半轻子衰变模$B_s^0\to π^+π^-\ell^+\ell^-$和$D_s^+\to π^+π^-\ell^+ ν$.这些过程对于确定S波$π^+π^-$光锥分布振幅是有价值的,其归一化是标量形状因子。我们比较的结果为标量形式的因素预测在unitarized手征微扰理论和提取的数据上的$B_s\to J/ψπ^+π^-$。然后,根据光锥求和规则计算了$B_s\to π^+π^-$和$D_s\to π^+π^-$的形状因子,并在此基础上对微分衰变宽度进行了预测。计算结果与$B_s$和$D_s$衰变为$π^+π^-$的实验数据符合得很好。未来在BEPC、LHC和KEKB上更精确的测量将有助于检验我们的形式和更精确地约束输入参数。

英文摘要:

In this work, we study the semileptonic decay modes $B_s^0\to π^+π^-\ell^+\ell^-$ and $D_s^+\to π^+π^-\ell^+ ν$ in the kinematics region where the $π^+π^-$ system has a invariant mass in the range $0.5$-$1.3$ GeV. These processes are valuable towards the determination of S-wave $π^+π^-$ light-cone distribution amplitudes whose normalizations are scalar form factors. We compare the results for scalar form factors predicted in unitarized chiral perturbation theory and extracted from the data on the $B_s\to J/ψπ^+π^-$. Then the $B_s\to π^+π^-$ and $D_s\to π^+π^-$ form factors are calculated in light-cone sum rules, based on which predictions for differential decay widths are made. The results are in good agreement with the experimental data on the $B_s$ and $D_s$ decays into $π^+π^-$. More accurate measurements at BEPC, LHC and KEKB in future will be helpful to examine our formalism and constrain the input parameters more precisely.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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