Gabyshev N, Abe K, Abe K, Adachi I, Aihara H, Asano Y, Aulchenko V, Aushev T, Bakich A M, Bitenc U, Bizjak I, Blyth S, Bondar A, Bozek A, Bracko M, Brodzicka J, Browder T E, Chang P, Chao Y, Chen A, Chen W T, Cheon B G, Chistov R, Choi S-K, Choi Y, Chuvikov A, Cole S, Dalseno J, Danilov M, Dash M, Drutskoy A, Eidelman S, Enari Y, Fratina S, Gershon T, Gokhroo G, Golob B, Gorisek A, Hara T, Hayashii H, Hazumi M, Hokuue T, Hoshi Y, Hou S, Hou W-S, Hsiung Y B, Iijima T, Imoto A, Inami K, Ishikawa A, Itoh R, Iwasaki M, Iwasaki Y, Kang J H, Kang J S, Kataoka S U, Katayama N, Kawai H, Kawasaki T, Khan H R, Kichimi H, Kim H J, Kim H O, Kim S K, Kim S M, Kinoshita K, Korpar S, Krokovny P, Kumar S, Kuo C C, Kuzmin A, Kwon Y-J, Lange J S, Leder G, Lesiak T, Lin S-W, Mandl F, Matsumoto T, Mikami Y, Mitaroff W, Miyake H, Miyata H, Mizuk R, Nagamine T, Nagasaka Y, Nakano E, Nakao M, Nakazawa H, Natkaniec Z, Nishida S, Nitoh O, Ogawa S, Ohshima T, Okabe T, Okuno S, Olsen S L, Onuki Y, Ozaki H, Palka H, Park C W, Park H, Parslow N, Peak L S, Pestotnik R, Piilonen L E, Rozanska M, Sagawa H, Sakai Y, Sato N, Schietinger T, Schneider O, Schwartz A J, Senyo K, Seuster R, Sevior M E, Shibuya H, Sidorov V, Singh J B, Somov A, Stamen R, Stanic S, Staric M, Sumiyoshi T, Suzuki S Y, Tajima O, Takasaki F, Tamai K, Tamura N, Tanaka M, Teramoto Y, Tian X C, Tsuboyama T, Tsukamoto T, Uehara S, Uglov T, Ueno K, Uno S, Urquijo P, Varner G, Varvell K E, Villa S, Wang C H, Wang M-Z, Xie Q L, Yabsley B D, Yamaguchi A, Yamamoto H, Yamashita Y, Yamauchi M, Yang Heyoung, Zhang C C, Zhang J, Zhang L M, Zhang Z P, Zhilich V, Zontar D
Budker Institute of Nuclear Physics, Novosibirsk.
Phys Rev Lett. 2006 Dec 15;97(24):242001. doi: 10.1103/PhysRevLett.97.242001. Epub 2006 Dec 11.
Using a sample of 152 x 10(6) BB pairs accumulated with the Belle detector at the KEKB e+e- collider, we study the decay mechanism of three-body charmed decay B- --> Lambdac+ ppi-. The intermediate two-body decay B--->Sigmac (2455)0 p is observed for the first time with a branching fraction of (3.7 +/- 0.7 +/- 0.4 +/- 1.0) x 10(-5) and a statistical significance of 8.4sigma. We also observe a low-mass enhancement in the (Lambdac+p) system, which can be parametrized as a Breit-Wigner function with a mass of (3.35(-0.02)(+0.01) +/-0.02) GeV/c2 and a width of (0.07(-0.03)(+0.04) +/-0.04) GeV/c2. We measure its branching fraction to be (3.9(-0.7)(+0.8) +/- 0.4 +/- 1.0) x 10(-5) with a statistical significance of 6.2sigma. The errors are statistical, systematic, and that of the Lambdac+-->pK- pi+ decay branching fraction.
利用在KEKB正负电子对撞机上的Belle探测器积累的152×10⁶个B⁻B⁺对样本，我们研究了三体粲夸克衰变B⁻→Λc⁺π⁻π⁰的衰变机制。首次观测到中间两体衰变B⁻→Σc(2455)⁰p，其分支比为(3.7±0.7±0.4±1.0)×10⁻⁵，统计显著性为8.4σ。我们还在(Λc⁺π⁻)系统中观测到一个低质量增强，它可以用一个 Breit-Wigner 函数来参数化，质量为(3.35(-0.02)(+0.01)±0.02)GeV/c²，宽度为(0.07(-0.03)(+0.04)±0.04)GeV/c²。我们测量其分支比为(3.9(-0.7)(+0.8)±0.4±1.0)×10⁻⁵，统计显著性为6.2σ。误差包括统计误差、系统误差以及Λc⁺→pK⁻π⁺衰变分支比的误差。
