Measurement of the Branching Ratio and Form Factors for the Decay \boldmath $K_L\toπ^{\pm}π^0e^{\mp}ν_e(\barν_e)

Abstract

The $K_L\to {\pi }^{\pm }{\pi }^0{e}^{\mp }{\nu }_e({\bar{\nu }}_e)$ decay was investigated with the NA48 detector at CERN SPS using a beam of long-lived neutral kaons. The branching ratio $Br(K_L\to {\pi }^{\pm }{\pi }^0{e}^{\mp }{\nu }_e({\bar{\nu }}_e))=(5.21\pm 0.07_{stat}\pm 0.09_{syst})\times 10^{-5}$ was fixed from a sample of 5464 events with 62 background events. The form factors ${\bar{f}}_s$, ${\bar{f}}_p$, ${\lambda }_g$ and $\bar{h}$ were found to be in agreement with previous measurements but with higher accuracy. The coupling parameter of the chiral Lagrangian $L_3=(-4.1\pm 0.2)\times 10^{-3}$ was evaluated from the data.

12 pages, 7 figures

Cited by in corpus (3)

• Kaon Decays in the Standard Model
• Comment on evidence for new interference phenomena in the decay D+ -> K- pi+ mu+ nu
• On V_ud determination from kaon decays