Paper detail

A Measurement of the KL Charge Asymmetry

We present a measurement of the charge asymmetry $δ_L$ in the mode $K_L \to π^{\pm}e^{\mp}ν$ based on 298 million analyzed decays. We measure a value of $δ_L = (3322 \pm 58(stat) \pm 47(sys))\cdot 10^{-6}$, in good agreement with previous measurements and 2.4 times more precise than the current best published result. The result is used to place more stringent limits on CPT and $ΔS = ΔQ$ violation in the neutral kaon system.