5 Measurement of K + → π 0 μ + νγ decay using stopped kaons

– 1 – Form Factors for Radiative Pion and Kaon Decays

The radiative decays, π ± → l ± νγ and K ± → l ± νγ, with l standing for an e or a μ, and γ for a real or virtual photon (e + e − pair), provide a powerful tool to investigate the hadronic structure of pions and kaons. The structure-dependent part SD i of the amplitude describes the emission of photons from virtual hadronic states, and is parametrized in terms of form factors F i , with i = V, ...

Measurement of direct photon emission in K + → π + π 0 γ decay using stopped positive kaons

s . in s - de t ] 1 5 M ay 2 00 2 Performance of a CsI ( Tl ) calorimeter in an experiment with stopped K + ’ s

The performance of the photon detector constructed for the search of T-violation in the decay K + → π 0 µ + ν is presented. The specific features of this detector consisting of 768 CsI(Tl) crystals with PIN photodiode readout for high precision measurement of T-odd correlations in decays of positive kaons are considered.

Improved Measurement of the π→eν Branching Ratio.

A new measurement of the branching ratio R_{e/μ}=Γ(π^{+}→e^{+}ν+π^{+}→e^{+}νγ)/Γ(π^{+}→μ^{+}ν+π^{+}→μ^{+}νγ) resulted in R_{e/μ}^{exp}=[1.2344±0.0023(stat)±0.0019(syst)]×10^{-4}. This is in agreement with the standard model prediction and improves the test of electron-muon universality to the level of 0.1%.

Apparatus for a Search for T-violating Muon Polarization in Stopped-Kaon Decays

The detector built at KEK to search for T-violating transverse muon polarization in K → πμνμ (Kμ3) decay of stopped kaons is described. Sensitivity to the transverse polarization component is obtained from reconstruction of the decay plane by tracking the μ through a toroidal spectrometer and detecting the π in a segmented CsI(Tl) photon calorimeter. The muon polarization was obtained from the ...