Observation of large CP violation in the neutral B meson system

K Abe; K Abe; R Abe; I Adachi; BS Ahn; H Aihara; M Akatsu; G Alimonti; K Asai; M Asai; Y Asano; T Aso; V Aulchenko; T Aushev; AM Bakich; E Banas; S Behari; PK Behera; D Beiline; A Bondar; A Bozek; TE Browder; BCK Casey; P Chang; Y Chao; KF Chen; BG Cheon; R Chistov; SK Choi; Y Choi; LY Dong; J Dragic; A Drutskoy; S Eidelman; V Eiges; Y Enari; R Enomoto; CW Everton; F Fang; H Fujii; C Fukunaga; M Fukushima; N Gabyshev; A Garmash; TJ Gershon; A Gordon; K Gotow; H Guler; R Guo; J Haba; H Hamasaki; K Hanagaki; F Handa; K Hara; T Hara; NC Hastings; H Hayashii; M Hazumi; EM Heenan; Y Higasino; I Higuchi; T Higuchi; T Hirai; H Hirano; T Hojo; T Hokuue; Y Hoshi; K Hoshina; SR Hou; WS Hou; SC Hsu; HC Huang; Y Igarashi; T Iijima; H Ikeda; K Ikeda; K Inami; A Ishikawa; H Ishino; R Itoh; G Iwai; H Iwasaki; Y Iwasaki; DJ Jackson; P Jalocha; HK Jang; M Jones; R Kagan; H Kakuno; J Kaneko; JH Kang; JS Kang; P Kapusta; N Katayama; H Kawai; H Kawai; Y Kawakami; N Kawamura; T Kawasaki; H Kichimi

Journal article

Observation of large CP violation in the neutral B meson system

K Abe, K Abe, R Abe, I Adachi, BS Ahn, H Aihara, M Akatsu, G Alimonti, K Asai, M Asai, Y Asano, T Aso, V Aulchenko, T Aushev, AM Bakich, E Banas, S Behari, PK Behera, D Beiline, A Bondar Show all

Physical Review Letters | AMER PHYSICAL SOC | Published : 2001

DOI: 10.1103/PhysRevLett.87.091802

Abstract

We present a measurement of the standard model CP violation parameter sin2ϕ1 based on a 29.1 fb−1 data sample collected at the γ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. One neutral B meson is fully reconstructed as a J/ψKS, ψ(2S)KS, χc1KS, ηcKS, J/ψKL, or J/ψK*0 decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2ϕ1=0.99±0.14(stat)±0.06(syst). We conclude that we have observed CP violation in the neutral B meson system. © 2001 The American Physical Society.