## Abstract

We calculate the electromagnetic corrections needed to obtain isospin invariant hadronic pion-pion s-wave scattering lengths a^{0}, a^{2} from the elements a_{cc}, a_{0c} of the s-wave scattering matrix for the (π^{+}π^{-},π^{0}π^{0}) system at the π^{+}π^{-} threshold. The latter can be extracted from experiments on the π^{+}π^{-} atom (pionium). Our calculation uses energy-independent hadronic pion-pion potentials V^{0} and V^{2} that satisfactorily reproduce the low-energy phase shifts given by two-loop chiral perturbation theory, with the hadronic mass of the pion taken first as the charged-pion mass and then as the neutral-pion mass. We also take into account an important relativistic effect whose inclusion influences the corrections considerably.

Original language | English |
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Pages (from-to) | 732-742 |

Number of pages | 11 |

Journal | Nuclear Physics A |

Volume | 699 |

Issue number | 3-4 |

DOIs | |

Publication status | Published - 11 Mar 2002 |