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arXiv · hep-ph/9911520

Pionium lifetime and ππscattering lengths in generalized chiral perurbation theory

H. Sazdjian
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Abstract

The relationship between the pionium lifetime and the $ππ$ scattering lengths is established, including the sizable electromagnetic corrections. The bound state formalism that is used is that of constraint theory which provides a covariant three-dimensional reduction of the Bethe--Salpeter equation. The framework of generalized chiral perturbation theory allows then an analysis of the lifetime value as a function of the $ππ$ scattering lengths, the latter being dependent on the quark condensate value.

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H. Sazdjian. 1999-11-29. Pionium lifetime and ππscattering lengths in generalized chiral perurbation theory. https://doi.org/10.1016/s0920-5632(00)00575-2

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