Improved measurement ofCP-violating parameters inB→ρ+ρ−decays

A Somov,H Miyata,M Starič,T Ohshima,K Inami,K Ueno,L E Piilonen,A Zupanc,H Stoeck,U Bitenc,H Hayashii,R Kulasiri,T Uglov,Y Watanabe,T Matsumoto,O Nitoh,R Pestotnik,M Shapkin,J Dragic,T Lesiak,J Schümann,T Nozaki,J Haba,Y Hoshi,H Kichimi,C H Wang,T Iijima,Y Miyazaki,P Pakhlov,A Vinokurova,S Uno,M Bračko,A Ishikawa,K Trabelsi,I Bizjak,K Kinoshita,Y Choi,G Gokhroo,A Drutskoy,S Ogawa,D Heffernan,T Sumiyoshi,H Sahoo,I Adachi,O Schneider,X C Tian,H J Hyun,B Golob,B Shwartz,H Ozaki,H Shibuya,G Pakhlova,M Dash,T Hara,A Yamaguchi,N Katayama,K Hayasaka,P Križan,C P Shen,H Miyake,K Senyo,S Villa,T E Browder,D H Kah,Z P Zhang,G R Moloney,A M Bakich,S L Olsen,R Chistov,J Dalseno,R Mizuk,M Iwasaki,Y Sakai,S Cole,T Hokuue,D Anipko,Y Usov,E Won,S Uehara,R Itoh,J H Kang,S Fratina,H Ha,S Okuno,Y Yamashita,I Bedny,M Nakao,A J Schwartz,T Aushev,F Takasaki,D Mohapatra,S Korpar,T Tsukamoto,M J Lee,S Eidelman,P Krokovny,A Chen,K Sumisawa,S Mconie,Y Teramoto,A Kuzmin,Y Onuki,B G Cheon,Y Chào ,K F Chen ,G Varner,V Aulchenko,Y Unno,H Ishino,H O Kim,P Wang,W.-S Hou,N Tamura,A Limosani,A Bondar,S W Lin ,M Tanaka,M Hazumi,I S Cho ,J S Lee,D Marlow,S E Lee,C C Kuo,C C Wang,Y J Kwon ,W Mitaroff,K E Varvell,B Yabsley ,N J Joshi ,P Urquijo,Y J Kim,C W Park,P Chang ,T Medvedeva,M Z Wang ,W T Chen,H Aihara,R Kumar

doi:10.1103/physrevd.76.011104

Abstract

We present a measurement of the CP-violating asymmetry in rho+rho- decays using 535 million BBbar pairs collected with the Belle detector at the KEKB e+e- collider. We measure CP-violating coefficients A = 0.16 +- 0.21(stat) +- 0.07 (syst) and S = 0.19 +- 0.30(stat) +- 0.07 (syst}. These values are used to determine the unitarity triangle angle phi_2 using an isospin analysis; the solution consistent with Standard Model lies in the range 53 < phi_2 < 114 deg. at 90 C.L.

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