Measurement of the Branching Ratio of the KL -> pi+pi- decay with the KLOE Detector

KLOE collaboration

doi:10.1016/j.physletb.2006.05.039

paper

Measurement of the Branching Ratio of the KL -> pi+pi- decay with the KLOE Detector

arXiv:hep-ex/0603041 · doi:10.1016/j.physletb.2006.05.039

Abstract

We present a measurement of the branching ratio of the CP violating decay KL->pi+pi- performed by the KLOE experiment at the phi factory DAFNE. We use 328 pb-1 of data collected in 2001 and 2002, corresponding to ~ 150 million tagged KL mesons. We find BR(KL->pi+pi-) = $(1.963 +/- 0.012 +/- 0.017)x 10^-3. This branching ratio measurement is fully inclusive of final-state radiation. Using the above result, we determine the modulus of the amplitude ratio |η_{+-}| to be (2.219 +/- 0.013)x 10^{-3} and |ε| to be (2.216 +/- 0.013)x 10^{-3}.

Subitted to Phys. Lett. B