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A Dispersive Treatment of $K_{\ell4}$ Decays

High Energy Physics - Phenomenology 2017-08-23 v1 High Energy Physics - Experiment Nuclear Theory

Abstract

K4K_{\ell4} are for several reasons an especially interesting decay channel of KK mesons: K4K_{\ell4} decays allow an accurate measurement of a combination of SS-wave ππ\pi\pi scattering lengths, one form factor of the decay is connected to the chiral anomaly and the decay is the best source for the determination of some low energy constants of ChPT. We present a dispersive approach to K4K_{\ell4} decays, which takes rescattering effects fully into account. Some fits to NA48/2 and E865 measurements and results of the matching to ChPT are shown.

Keywords

Cite

@article{arxiv.1209.0755,
  title  = {A Dispersive Treatment of $K_{\ell4}$ Decays},
  author = {Gilberto Colangelo and Emilie Passemar and Peter Stoffer},
  journal= {arXiv preprint arXiv:1209.0755},
  year   = {2017}
}

Comments

4 pages, talk given by PS at MESON2012 - 12th International Workshop on Meson Production, Properties and Interaction, Krak\'ow, Poland, 31 May - 5 June 2012