Journal article

Evidence for direct CP violation in B-0 -> K pi(-) decays

Y Chao, P Chang, K Abe, K Abe, N Abe, I Adachi, H Aihara, K Akai, M Akatsu, M Akemoto, Y Asano, T Aso, V Aulchenko, T Aushev, T Aziz, S Bahinipati, AM Bakich, Y Ban, M Barbero, A Bay Show all

Physical Review Letters | AMER PHYSICAL SOC | Published : 2004

Abstract

We report evidence for direct CP violation in the decay B0-->K+pi(-) with 253 fb(-1) of data collected with the Belle detector at the KEKB e(+)e(-) collider. Using 275x10(6) BB pairs we observe a B-->K+/-pi(-/+) signal with 2140+/-53 events. The measured CP violating asymmetry is A(CP)(K+pi(-))=-0.101+/-0.025(stat)+/-0.005(syst), corresponding to a significance of 3.9sigma including systematics. We also search for CP violation in the decays B+-->K+pi(0) and B+-->pi(+)pi(0). The measured CP violating asymmetries are A(CP)(K+pi(0))=0.04+/-0.05(stat)+/-0.02(syst) and A(CP)(pi(+)pi(0))=-0.02+/-0.10(stat)+/-0.01(syst), corresponding to the intervals -0.05View full abstract