Speaker
Monica Pepe
(INFN Perugia)
Description
We report our final result on the measurement of direct photon emission
(DE) in the decay K+- -> pi+- pi0 gamma and its interference (INT) with
the inner bremsstrahlung amplitude. For this measurement the full NA48/2
data set with about 600k reconstructed K+- -> pi+- pi0 gamma decays was
analyzed, which is factor of 30 larger than for previous experiments and
a factor of three w.r.t. our preliminary result.
From this, the sizes of both the DE and the INT amplitudes have been
measured with high precision, with the INT amplitude being observed for
the first time. In addition, the CP violating asymmetry between K+ and K- has been
obtained to be less than 103 in this channel.
We also report on the measurement of the branching fraction of the rare decay
K+- -> pi+- gamma gamma using the full NA48/2 dataset of more than 5000
reconstructed decays from the full NA48/2 data set.
From the spectrum of the invariant gamma gamma mass, the decay
parameter c^ can be extracted with unprecedented precision.
Finally, we report on the measurement of more than 200000 events of the decay K+-
-> pi0 e+- nu_e gamma, recorded with the NA48/2 detector at CERN.
These statistics, about two orders of magnitude more than previous
experiments, allow measurements of the decay rate and of possible CP
violation in this decay with per cent precision.
Primary author
Monica Pepe
(INFN Perugia)
