Speaker
Marc Knecht
(CNRS/CPT, Marseille)
Description
The very precise data obtained by the NA48/2 collaboration at the CERN SPS on the decay channels K^\pm \to \pi^+ \pi^- e^\pm \stackrel{_{(-)}}{\nu_e}$ and $K^\pm \to \pi^0 \pi^0 e^\pm \stackrel{_{(-)}}{\nu_e}$ have made it necessary to address issues related to isospin breaking. Three aspects related to this issue will be considered: isospin breaking due to the pion mass difference in the phases of the form factors for the $K^\pm \to \pi^+ \pi^- e^\pm \stackrel{_{(-)}}{\nu_e}$ decay amplitude, the cusp in the decay distribution of the $K^\pm \to \pi^0 \pi^0 e^\pm \stackrel{_{(-)}}{\nu_e}$ mode, and radiative corrections.
Primary author
Marc Knecht
(CNRS/CPT, Marseille)
