Abe K, Abe K, Abe N, Abe T, Adachi I, Aihara H, Akai K, Akatsu M, Akemoto M, Asano Y, Aso T, Aulchenko V, Aushev T, Bakich A M, Ban Y, Banerjee S, Bay A, Bedny I, Bizjak I, Bondar A, Bozek A, Bracko M, Browder T E, Chao Y, Chen K F, Cheon B G, Chistov R, Choi S K, Choi Y, Chuvikov A, Cole S, Danilov M, Dragic J, Drutskoy A, Eidelman S, Eiges V, Enari Y, Epifanov D, Flanagan J, Furukawa K, Gabyshev N, Garmash A, Gershon T, Golob B, Haba J, Hara K, Hastings N C, Hayashii H, Hazumi M, Hinz L, Hokuue T, Hoshi Y, Hou W S, Hsiung Y B, Huang H C, Iijima T, Ikeda H, Inami K, Ishikawa A, Ishino H, Itoh R, Iwasaki H, Iwasaki M, Iwasaki Y, Kakuno H, Kamitani T, Kang J H, Kang J S, Kapusta P, Kataoka S U, Katayama N, Kawai H, Kawasaki T, Kibayashi A, Kichimi H, Kikutani E, Kim H J, Kim J H, Kim S K, Kinoshita K, Koppenburg P, Korpar S, Krizan P, Krokovny P, Kumar S, Kuzmin A, Kwon Y J, Lange J S, Leder G, Lee S H, Lee Y J, Lesiak T, Li J, Limosani A, Lin S W, Liventsev D, MacNaughton J, Mandl F, Marlow D, Matsumoto H, Matsumoto T, Matyja A, Michizono S, Mimashi T, Mitaroff W, Miyabayashi K, Miyake H, Miyata H, Mohapatra D, Moloney G R, Murakami A, Nagamine T, Nagasaka Y, Nakadaira T, Nakamura T T, Nakano E, Nakao M, Nakazawa H, Natkaniec Z, Neichi K, Nishida S, Nitoh O, Noguchi S, Nozaki T, Ogawa S, Ogawa Y, Ohmi K, Ohshima T, Ohuchi N, Oide K, Okabe T, Okuno S, Olsen S L, Ostrowicz W, Ozaki H, Pakhlov P, Palka H, Park C W, Park H, Parslow N, Piilonen L E, Root N, Rozanska M, Sagawa H, Sakai Y, Schneider O, Schümann J, Schwanda C, Schwartz A J, Semenov S, Senyo K, Shibuya H, Shidara T, Shwartz B, Sidorov V, Singh J B, Soni N, Stamen R, Stanic S, Staric M, Sugahara R, Sumisawa K, Sumiyoshi T, Suzuki K, Suzuki S, Tajima O, Takasaki F, Tamai K, Tamura N, Tanaka M, Tawada M, Teramoto Y, Tomura T, Tsuboyama T, Tsukamoto T, Uehara S, Uglov T, Ueno K, Unno Y, Uno S, Varner G, Varvell K E, Wang C C, Wang C H, Wang M Z, Watanabe Y, Yabsley B D, Yamada Y, Yamaguchi A, Yamashita Y, Yamauchi M, Yanai H, Yang Heyoung, Ying J, Yokoyama M, Yoshida M, Yusa Y, Zhang C C, Zhang Z P, Ziegler T, Zontar D, Zürcher D
High Energy Accelerator Research Organization (KEK), Tsukuba.
Phys Rev Lett. 2004 Jul 9;93(2):021601. doi: 10.1103/PhysRevLett.93.021601. Epub 2004 Jul 6.
We report the first observation of CP violation in B0-->pi(+)pi(-) decays based on 152x10(6) gamma (4S)-->BB decays collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We reconstruct a B0-->pi(+)pi(-) CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the distribution of the time intervals between the two B meson decay points, we obtain A(pipi)=+0.58+/-0.15(stat)+/-0.07(syst) and S(pipi)=-1.00+/-0.21(stat)+/-0.07(syst). We rule out the CP-conserving case, A(pipi)=S(pipi)=0, at a level of 5.2 standard deviations. We also find evidence for direct CP violation with a significance at or greater than 3.2 standard deviations for any S(pipi) value.
我们基于在KEKB非对称能量正负电子对撞机上使用Belle探测器收集的152×10⁶次γ(4S)→BB衰变，首次观测到B⁰→π⁺π⁻衰变中的CP破坏。我们重建了一个B⁰→π⁺π⁻CP本征态，并根据其衰变产物确定伴随的B介子的味道。从两个B介子衰变点之间的时间间隔分布，我们得到A(ππ)= +0.58±0.15(统计)±0.07(系统)和S(ππ)= -1.00±0.21(统计)±0.07(系统)。我们在5.2个标准差的水平上排除了CP守恒情况，即A(ππ)=S(ππ)=0。我们还发现了直接CP破坏的证据，对于任何S(ππ)值，其显著性等于或大于3.2个标准差。
