Pakhlova G, Adachi I, Aihara H, Arinstein K, Aulchenko V, Aushev T, Bakich A M, Balagura V, Bedny I, Bhardwaj V, Bitenc U, Bondar A, Bozek A, Bracko M, Brodzicka J, Browder T E, Chang P, Chen A, Cheon B G, Chiang C-C, Chistov R, Cho I-S, Choi S-K, Choi Y, Dalseno J, Danilov M, Dash M, Eidelman S, Gabyshev N, Ha H, Haba J, Hayasaka K, Hazumi M, Heffernan D, Hoshi Y, Hou W-S, Hsiung Y B, Hyun H J, Iijima T, Inami K, Ishikawa A, Ishino H, Itoh R, Iwasaki M, Iwasaki Y, Kah D H, Kang J H, Katayama N, Kawai H, Kawasaki T, Kichimi H, Kim H J, Kim H O, Kim S K, Kim Y I, Kim Y J, Kinoshita K, Krizan P, Krokovny P, Kumar R, Kuzmin A, Kwon Y-J, Kyeong S-H, Lange J S, Lee J S, Lee S E, Lesiak T, Li J, Limosani A, Liu C, Liventsev D, Mandl F, Matyja A, Miyabayashi K, Miyata H, Miyazaki Y, Mizuk R, Mori T, Nakano E, Nakao M, Natkaniec Z, Nishida S, Nitoh O, Noguchi S, Ogawa S, Ohshima T, Okuno S, Olsen S L, Ozaki H, Pakhlov P, Palka H, Park C W, Park H, Park H K, Peak L S, Piilonen L E, Poluektov A, Sahoo H, Sakai Y, Schneider O, Senyo K, Shapkin M, Shen C P, Shiu J-G, Shwartz B, Singh J B, Sokolov A, Stanic S, Staric M, Sumiyoshi T, Tanaka M, Taylor G N, Teramoto Y, Tikhomirov I, Uehara S, Uglov T, Unno Y, Uno S, Urquijo P, Usov Y, Varner G, Wang C H, Wang M-Z, Wang P, Wang X L, Watanabe Y, Wedd R, Won E, Yabsley B D, Yamashita Y, Yamauchi M, Yuan C Z, Zhang C C, Zhang Z P, Zhilich V, Zhulanov V, Zivko T, Zupanc A, Zyukova O
Institute for Theoretical and Experimental Physics, Moscow.
Phys Rev Lett. 2008 Oct 24;101(17):172001. doi: 10.1103/PhysRevLett.101.172001.
We report a measurement of the exclusive e+ e- -->Lambda+(c)Lambda-(c) cross section as a function of center-of-mass energy near the Lambda+(c)Lambda-(c) threshold. A clear peak with a significance of 8.2sigma is observed in the Lambda+(c)Lambda-(c) invariant mass distribution just above threshold. With an assumption of a resonance origin for the observed peak, a mass and width of M=[4634 (+8)(-7)(stat)(+5)(-8)(syst)] MeV/c(2) and Gamma_(tot)=[92 (+40)(-24)(stat)(+10)(-21)(syst)] MeV are determined. The analysis is based on a study of events with initial-state-radiation photons in a data sample collected with the Belle detector at the Upsilon(4S) resonance and nearby continuum with an integrated luminosity of 695 fb(-1) at the KEKB asymmetric-energy e+ e- collider.
我们报告了在质心能量接近Λ⁺cΛ⁻c阈值时，对专属e⁺e⁻→Λ⁺cΛ⁻c截面作为质心能量函数的测量结果。在略高于阈值的Λ⁺cΛ⁻c不变质量分布中，观察到一个显著性为8.2σ的清晰峰。假设观察到的峰源于共振，确定了质量和宽度分别为M = [4634 (+8)(-7)(统计)(+5)(-8)(系统)] MeV/c²和Γtot = [92 (+40)(-24)(统计)(+10)(-21)(系统)] MeV。该分析基于对在KEKB非对称能量e⁺e⁻对撞机的Υ(4S)共振及附近连续区收集的数据样本中，带有初态辐射光子的事件的研究，积分亮度为695 fb⁻¹，探测器为Belle。
