Seminar on Theoretical Nuclear Physics

12.04.11 16:15

A dispersive treatment of Kl4 decays

Peter Stoffer (Bern)

Kl4 are semileptonic decays of K mesons with a branching ratio of some 10-5.  For several reasons, this is an especially interesting decay channel: Kl4 decays allow an accurate measurement of a combination of S-wave 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.  A dispersive approach to Kl4 decays will be presented, which neglects discontinuities in D- and higher waves but takes rescattering effects fully into account.  Some fits to NA48/2 measurements and results of the matching to ChPT will be shown.


(Seminarraum II)

Category: Kernphysik