For three-body hadron decays mediated by intermediate resonances with large widths, we show how to properly extract the quasi-two-body decay rates for a meaningful comparison with the corresponding theoretical estimates, using several $B$ decays as explicit examples. We compute the correction factor from finite width effects in the QCD factorization approach, and make a comparison with that using the experimental parameterization in which the momentum dependence in the weak dynamics is absent. Although the difference is generally less than $10\%$ for tensor and vector resonances, it can be as large as $(25-40)\%$ for scalar resonances. Our finding can in fact be applied to general quasi-two-body decays.

中文翻译：

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共振三体衰变中的宽度效应：以 B 衰变为例

对于由大宽度中间共振介导的三体强子衰变，我们展示了如何正确提取准双体衰变率，以便与相应的理论估计值进行有意义的比较，使用几个 $B$ 衰变作为明确的例子。我们从 QCD 分解方法中的有限宽度效应计算校正因子，并与使用实验参数化的方法进行比较，其中弱动力学中的动量依赖性不存在。尽管张量和矢量共振的差异通常小于 $10\%$，但对于标量共振，它可能会大到 $(25-40)\%$。我们的发现实际上可以应用于一般的准二体衰变。