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Journal of High Energy Physics

, Volume 2011, Issue 2, pp 1–48 | Cite as

Rescattering effects in η → 3π decays

  • Sebastian P. SchneiderEmail author
  • Bastian Kubis
  • Christoph Ditsche
Article

Abstract

The isospin-breaking decay η → 3π is an ideal tool to extract information on light quark mass ratios from experiment. For a precise determination, however, a detailed description of the Dalitz plot distribution is necessary. In that respect, in particular the slope parameter α of the neutral decay channel causes some concern, since the one-loop prediction from chiral perturbation theory misses the experimental value substantially. We use the modified non-relativistic effective field-theory, a dedicated framework to analyze final-state interactions beyond one loop including isospin-breaking corrections, to extract charged and neutral Dalitz plot parameters. Matching to chiral perturbation theory at next-to-leading order, we find α = −0.025 ± 0.005, in marginal agreement with experimental findings. We derive a relation between charged and neutral decay parameters that points towards a significant tension between the most recent KLOE measurements of these observables.

Keywords

Quark Masses and SM Parameters Chiral Lagrangians 

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Copyright information

© SISSA, Trieste, Italy 2011

Authors and Affiliations

  • Sebastian P. Schneider
    • 1
    Email author
  • Bastian Kubis
    • 1
  • Christoph Ditsche
    • 1
  1. 1.Helmholtz-Institut für Strahlen-und Kernphysik (Theorie) and Bethe Center for Theoretical PhysicsUniversität BonnBonnGermany

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