Decays of the $pi^{+}pi^{-}$ atom
Decays of the $pi^{+}pi^{-}$ atom
复制标题
$pi^{ }pi^{-}$ 原子的衰变
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
A. Gall
中科院分区：
文献类型：
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作者：
J. Gasser;V. Lyubovitskij;A. Rusetsky;A. Gall
我们构造了一个有效的非相对论量子场论来描述π + π-对的束缚态及其强子衰变。然后，我们推导出一个一般表达式的基态的寿命在下一个领导秩序的同位旋破缺。手征微扰理论允许一个相关的衰减率的两个S波π π散射长度和几个低能量常数，发生在手征拉格朗日。最近对散射长度的预测给出τ =（2.9 μ m 0.1）* 10^{-15}秒。这个结果可能会遇到π + π-寿命测量，就像目前在欧洲核子研究中心进行的那样。
We construct an effective non-relativistic quantum field theory that describes bound states of pi+ pi- pairs and their hadronic decays. We then derive a general expression for the lifetime of the ground state at next-to-leading order in isospin breaking. Chiral perturbation theory allows one to relate the decay rate to the two S-wave pi pi scattering lengths and to several low-energy constants that occur in the chiral Lagrangian. Recent predictions for the scattering lengths give tau = (2.9 pm 0.1) * 10^{-15} sec. This result may be confronted with pi+ pi- lifetime measurements, like the one presently carried out at CERN.