Johan Bijnens, Fredrik Borg
Isospin Breaking in K > 3 Pi Decays III:
Bremsstrahlung and Fit to Experiment
Abstract
We complete here our work on isospin violation in the
$K\to3\pi$ system. We first calculate $K\to2\pi$ to the
same order as we did $K\to3\pi$ in papers I and II of this
series. This adds effects of order $G_{27} p^2 (m_um_d)$
and $G_{27} p^2 e^2$ to earlier work. We calculate also the
lowest order Bremsstrahlung contributions,
$K\to2\pi\gamma,3\pi\gamma$. With these and our earlier
results we perform a full fit to all available CP
conserving data in the $K\to2\pi,3\pi$ system including
isospin violation effects. We perform these fits under
various input assumptions as well as test the factorization
and the vector dominance model for the weak NLO low energy
constants.
LU TP 0440, hepph/0501163
