Ishino H, Abe K, Abe K, Adachi I, Aihara H, Anipko D, Arinstein K, Aushev T, Bakich A M, Barberio E, Barbero M, Bedny I, Bitenc U, Bizjak I, Blyth S, Bozek A, Bracko M, Browder T E, Chang M-C, Chang P, Chao Y, Chen A, Chen K-F, Chen W T, Cheon B G, Chistov R, Choi Y, Choi Y K, Cole S, Dalseno J, Dash M, Drutskoy A, Eidelman S, Fratina S, Gershon T, Go A, Gokhroo G, Golob B, Gorisek A, Ha H, Haba J, Hara K, Hayasaka K, Hazumi M, Heffernan D, Hokuue T, Hoshi Y, Hou S, Hsiung Y B, Iijima T, Imoto A, Inami K, Ishikawa A, Iwasaki Y, Kang J H, Kapusta P, Kataoka S U, Katayama N, Kawai H, Kawasaki T, Khan H R, Kibayashi A, Kichimi H, Kinoshita K, Korpar S, Krizan P, Krokovny P, Kulasiri R, Kumar R, Kuo C C, Kusaka A, Kuzmin A, Kwon Y-J, Lee M J, Lee S E, Lesiak T, Limosani A, Lin S-W, MacNaughton J, Mandl F, Marlow D, Matsumoto T, Matyja A, McOnie S, Mitaroff W, Miyabayashi K, Miyake H, Miyata H, Miyazaki Y, Mizuk R, Mohapatra D, Nagasaka Y, Nakano E, Nakao M, Nishida S, Nitoh O, Nozaki T, Ogawa S, Ohshima T, Olsen S L, Onuki Y, Ozaki H, Pakhlov P, Pakhlova G, Park H, Peak L S, Pestotnik R, Piilonen L E, Sahoo H, Sakai Y, Satoyama N, Schietinger T, Schneider O, Schümann J, Schwanda C, Schwartz A J, Seidl R, Senyo K, Sevior M E, Shibuya H, Shwartz B, Somov A, Soni N, Stanic S, Staric M, Stoeck H, Sumisawa K, Sumiyoshi T, Suzuki S Y, Tajima O, Takasaki F, Tamai K, Tamura N, Tanaka M, Teramoto Y, Tian X C, Trabelsi K, Tsukamoto T, Uehara S, Ueno K, Unno Y, Uno S, Urquijo P, Ushiroda Y, Usov Y, Varner G, Varvell K E, Villa S, Wang C H, Wang M-Z, Watanabe Y, Won E, Wu C-H, Xie Q L, Yabsley B D, Yamaguchi A, Yamashita Y, Yamauchi M, Zhang L M, Zhang Z P, Zhilich V, Zupanc A
Tokyo Institute of Technology, Tokyo.
Phys Rev Lett. 2007 May 25;98(21):211801. doi: 10.1103/PhysRevLett.98.211801. Epub 2007 May 21.
We report a new measurement of the time-dependent CP-violating parameters in B(0)-->pi(+)pi(-) decays with 535 x 10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider operating at the Upsilon(4S) resonance. We find 1464+/-65 B(0)-->pi(+)pi(-) events and measure the CP-violating parameters S(pipi)=-0.61+/-0.10(stat)+/-0.04(syst) and A(pipi)=+0.55+/-0.08(stat)+/-0.05(syst). We observe large direct CP violation with a significance greater than 5 standard deviations for any S(pipi) value. Using isospin relations, we measure the Cabibbo-Kobayashi-Maskawa quark-mixing matrix angle phi(2)=(97+/-11) degrees for the solution consistent with the standard model and exclude the range 11 degrees <phi(2)<79 degrees at the 95% confidence level.
我们报告了在KEKB非对称能量正负电子对撞机的宇普西隆（4S）共振态下，利用Belle探测器收集的535×10⁶对BB介子对，对B⁰→π⁺π⁻衰变中随时间变化的CP破坏参数进行的新测量。我们发现了1464±65个B⁰→π⁺π⁻事件，并测量了CP破坏参数S(ππ)= -0.61±0.10（统计）±0.04（系统）和A(ππ)= +0.55±0.08（统计）±0.05（系统）。对于任何S(ππ)值，我们都观察到了显著的直接CP破坏，其显著性大于5个标准差。利用同位旋关系，对于与标准模型一致的解，我们测量了卡比博-小林-益川夸克混合矩阵角φ₂=(97±11)°，并在95%置信水平下排除了11°<φ₂<79°的范围。
