A NEW MEASUREMENT OF THE RADIATIVE K_e3 BRANCHING RATIO AND PHOTON SPECTRUM

摘要

We present a preliminary report on a new measurement of the ra- diative K_e3 branching ratio and the first study of the photon spectrum in this decay. We find BR(K_e3γ,E_γ>30GeV,θ_eγ>20°)/BR(K_e3)= 0. 911±0.009(stat)~+0.021_-0.010(syst.)/100. Our measurement of the spectrum is consistent with inner bremsstrahlung only as the source of photons at the 2σ level.