Kaon International Conference

Session

Session II

3

22 May 2007, 10:50

High Energy Building - Aula Bruno Touschek (Laboratori Nazionali di Frascati dell'INFN)

Conveners

Session II: CP and T violation

• Johan Bijnens (Lund Univ.)

Session II: Radiative Decays

• Giancarlo D'Ambrosio (Naples Univ. and INFN)

13. Lattice progress on non-leptonic decays

Prof. Christopher Sachrajda (Southampton University)

22/05/2007, 10:50

Non leptonic/ radiative decays

The precise evaluation of K to pi pi decay amplitudes is one of the most important goals and milestones for Lattice QCD and an area of particle physics where lattice simulations can make a very significant impact. I will review recent theoretical progress (including the so-called "infrared problem"), the current status of the numerical results and the prospects for future developments.

38. ChPT progress on non-leptonic and radiative decays

Prof. Joaquim Prades (Granada University)

22/05/2007, 11:20

Non leptonic/ radiative decays

I discuss selected topics on non-leptonic and radiative kaon decays mainly related to direct CP-violation within the combined ChPT and large N_c approaches.

14. Lattice progress on epsilon-prime

Prof. Robert Mawhinney (Columbia University)

22/05/2007, 11:50

Non leptonic/ radiative decays

55. Measurement of the CP violation parameter $|\eta_{+-}|$ and the charge asymmetry in $K^\pm \to 3\pi$ decays by NA48 and NA48/2

Dr Andreas Winhart (Institut fuer Physik, Universitaet Mainz)

22/05/2007, 12:20

Non leptonic/ radiative decays

The main goal of the NA48 experiment at the CERN SPS has been the search for direct CP violation (CPV) in kaon decays. The observable $\eta_{+-}$ is related to the parameters of indirect and direct CPV ($\eta_{+-} = \varepsilon + \varepsilon^\prime$) and defined as the CP violating amplitude ratio of the neutral kaon decaying into two charged pions: $\eta_{+-} = A(K_L \to...

30. A new $ K^{0}_{L} $ decay channel

Prof. Antonino Pullia (Universita` di Milano Bicocca and INFN)

22/05/2007, 12:40

Non leptonic/ radiative decays

The rate for the decay $ K^{0}_{L} \Rightarrow K^{\pm} e^{\mp}(\overline {\nu}/\nu) $ of (0.0979 $\pm 0.0037 $) $ s^{-1} $ has been calculated in the hypothesis of the conserved vector current and , assuming the CP violation very small , the two rates for the decay $\overline{ K^{0}_{L}}\Rightarrow K^{-} e^{+} \nu $ and $ K^{0}_{L} \Rightarrow K^{+} e^{-} \overline {\nu} $ are...

56. Measurement of T-violating transverse muon polarization in $K^+ \rightarrow \pi^0 \mu^+ \nu$ decay at J-PARC

Dr Suguru Shimizu (Osaka University)

22/05/2007, 13:00

Non leptonic/ radiative decays

As a precision frontier experiment at J-PARC, we proposed a search for time reversal invariance violation by measuring the transverse muon polarization (Pt) in the $K^+ \rightarrow \pi^0 \mu^+ \nu$ (Kmu3) decay which constitutes a T-odd observable. This observable is one of the few test of T-invariance and the corresponding CP violation in non-neutral meson sector and is sensitive to...

57. Radiative and semileptonic decays in Chiral Perturbation Theory

Prof. Johan Bijnens (Lund University)

22/05/2007, 14:30

Non leptonic/ radiative decays

I will give an overview of the recent results in ChPT relevant for kaon physics including K_l3 and K_l4 at two-loop order.

50. New precise measurements of radiative charged kaon and hyperon decays

Dr Ermanno Imbergamo (Universita' di Perugia)

22/05/2007, 14:50

Non leptonic/ radiative decays

The NA48/2-Experiment at the CERN SPS has recorded more than 2 billion charged kaon decays. From a sub-sample of this data set we have selected about 2 x 10^5 practically background free events of the decay K+- -> pi+- pi0 gamma, which is an order of magnitude more than from any previous experiment. The decay K+- -> pi+- pi0 gamma is dominated by Inner Bremsstrahlung (IB) of the...

29. Study of K^(-) into e,nu,pi^(0),gamma decay with ISTRA setup

Prof. Vladimir Bolotov (Institute for Nuclear Research of RAS)

22/05/2007, 15:10

Non leptonic/ radiative decays

Results of study of the negative kaon into electron,neutrino, neutral pion, gamma decay at ISTRA setup are presented. 4476 events of this decay have been observed. The branching ratio to be Br=(3,06+- 0.09+-0.14)x10^(-4) for E>30 MeV and theta>20deg. For the asymmetry A=-0.015+-0.021. At present it is the best estimate of the asymmetry.

67. KLOE measurement of $BR(K_L \rightarrow \pi e \nu \gamma)$.

Dr Marco Dreucci (LNF- INFN)

22/05/2007, 15:30

Non leptonic/ radiative decays

The study of radiative $K_L$ decays offers the possibility to obtain informations on kaon structure and to test predictions of the Chiral Perturbation Theory. Two different processes contribute to photon emission in $K_L \rightarrow \pi e \nu \gamma$ decay ($K_{Le3\gamma}$): the inner bremsstrahlung (IB) and the direct emission (DE). The latter is due to photon radiation from...

80. Radiative decay results from KTeV

Prof. Elliott Cheu (Arizona University)

22/05/2007, 15:50

Non leptonic/ radiative decays

The KteV experiment has carried out a broad program of studies of rare kaon decays. In this talk we present results on KL-> pi0 gamma gamma, KL-> pi0 e+ e- gamma and KL-> pi+ e- nu e+ e- . These decays provide a window for testing chiral perurbation theory at O(p^6). We find BR(KL-> pi0 pi0 gamma)= (1.30 +/- 0.03 +/- 0.04)E-6, BR(KL-> pi0 e+ e- gamma)= (1.9 +/- 0.16 +/- 0.12)E-8, and ...

76. KLOE measurements of the BR(Ks into gamma gamma) and direct search for Ks into e+e-

Dr Matteo Martini (LNF -INFN)

22/05/2007, 16:10

Non leptonic/ radiative decays

A precise measurement of the $K_S \rightarrow \gamma \gamma$ rate is an important test of Chiral Perturbation Theory predictions. The decay amplitude can be evaluated at the leading $p^4$ order providing an estimate of the $BR$ for this decay of $(2.1\pm0.1)\times10^{-6}$. The latest experimental determination of $BR(K_S \rightarrow \gamma \gamma)$ is a precise measurement from NA48,...