Using a sample of over 400 million φ→KSKL decays produced during the years 2001 and 2002 at the DAΦNE e+e- collider, the ratio RS π=Γ(KS→π+π-(γ))/Γ(KS→π0π0) has been measured with the KLOE detector. The result is RS π=2.2555±0.0012stat±0.0021corr-stat±0.0050syst, which is in good agreement with the previously published result based on the KLOE data sample from the year 2000. The average of the KLOE results is RS π=2.2549±0.0054, reducing the total error by a factor of three, to 0.25%.
AMBROSINO F., CERADINI FILIPPO, DI MICCO BIAGIO, & FEDERICO NGUYEN (2006). Precise measurement of Γ(KS→π+π-(γ))/Γ(KS→π0π0) with the KLOE detector at DAΦNE. EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 48, 767-780.