English

Cusps in K --> 3 pi decays

High Energy Physics - Phenomenology 2008-11-26 v1

Abstract

The pion mass difference generates a pronounced cusp in K --> 3 pi decays. As has recently been pointed out by Cabibbo and Isidori, an accurate measurement of the cusp may allow one to pin down the S-wave pi pi scattering lengths to high precision. Here, we present and illustrate an effective field theory framework that allows one to determine the structure of this cusp in a straightforward manner. The strictures imposed by analyticity and unitarity are respected automatically.

Keywords

Cite

@article{arxiv.hep-ph/0604084,
  title  = {Cusps in K --> 3 pi decays},
  author = {Gilberto Colangelo and Juerg Gasser and Bastian Kubis and Akaki Rusetsky},
  journal= {arXiv preprint arXiv:hep-ph/0604084},
  year   = {2008}
}

Comments

14 pages, 3 figures, uses Elsevier style

R2 v1 2026-07-22T14:07:58.384Z