https://doi.org/10.1140/epjc/s10052-009-1054-7
Regular Article - Theoretical Physics
The cusp effect in η′→η π π decays
Helmholtz-Institut für Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universität Bonn, 53115, Bonn, Germany
* e-mail: kubis@itkp.uni-bonn.de
Received:
9
April
2009
Revised:
6
May
2009
Published online:
3
June
2009
Strong final-state interactions create a pronounced cusp in η′→η π 0 π 0 decays. We adapt and generalize the non-relativistic effective field theory framework developed for the extraction of π π scattering lengths from K→3π decays to this case. The cusp effect is predicted to have an effect of more than 8% on the decay spectrum below the π + π − threshold.
PACS: 11.30.Rd – / 13.25.Jx – / 13.75.Lb –
© Springer-Verlag , 2009
