Asner D M, Dytman S A, Mehrabyan S, Mueller J A, Nam S, Savinov V, Huang G S, Miller D H, Pavlunin V, Sanghi B, Shibata E I, Shipsey I P J, Adams G S, Chasse M, Cummings J P, Danko I, Napolitano J, Cronin-Hennessy D, Park C S, Park W, Thayer J B, Thorndike E H, Coan T E, Gao Y S, Liu F, Stroynowski R, Artuso M, Boulahouache C, Blusk S, Butt J, Dambasuren E, Dorjkhaidav O, Haynes J, Menaa N, Mountain R, Muramatsu H, Nandakumar R, Redjimi R, Sia R, Skwarnicki T, Stone S, Wang J C, Zhang Kevin, Mahmood A H, Csorna S E, Bonvicini G, Cinabro D, Dubrovin M, Bornheim A, Lipeles E, Pappas S P, Shapiro A, Weinstein A J, Mahapatra R, Nelson H N, Briere R A, Chen G P, Ferguson T, Tatishvili G, Vogel H, Watkins M E, Adam N E, Alexander J P, Berkelman K, Boisvert V, Cassel D G, Duboscq J E, Ecklund K M, Ehrlich R, Galik R S, Gibbons L, Gittelman B, Gray S W, Hartill D L, Heltsley B K, Hsu L, Jones C D, Kandaswamy J, Kreinick D L, Kuznetsov V E, Magerkurth A, Mahlke-Krüger H, Meyer T O, Patterson J R, Pedlar T K, Peterson D, Pivarski J, Riley D, Sadoff A J, Schwarthoff H, Shepherd M R, Sun W M, Thayer J G, Urner D, Wilksen T, Weinberger M, Athar S B, Avery P, Breva-Newell L, Potlia V, Stoeck H, Yelton J, Eisenstein B I, Gollin G D, Karliner I, Lowrey N, Naik P, Sedlack C, Selen M, Thaler J J, Williams J, Edwards K W, Besson D, Gao K Y, Gong D T, Kubota Y, Li S Z, Poling R, Scott A W, Smith A, Stepaniak C J, Urheim J, Metreveli Z, Seth K K, Tomaradze A, Zweber P, Arms K, Eckhart E, Gan K K, Gwon C, Severini H, Skubic P
University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Phys Rev Lett. 2004 Apr 9;92(14):142001. doi: 10.1103/PhysRevLett.92.142001. Epub 2004 Apr 5.
We report on the observation of the eta(')(c)(2(1)S0), the radial excitation of the eta(c)(1(1)S0) ground state of charmonium, in the two-photon fusion reaction gammagamma-->eta(')(c)-->K(0)(S)K+/-pi(-/+) in 13.6 fb(-1) of CLEO II/II.V data and 13.1 fb(-1) of CLEO III data. We obtain M(eta(')(c))=3642.9+/-3.1(stat)+/-1.5(syst) MeV and M(eta(c))=2981.8+/-1.3(stat)+/-1.5(syst) MeV. The corresponding values of hyperfine splittings between 1S0 and 3S1 states are DeltaM(hf)(1S)=115.1+/-2.0 MeV and DeltaM(hf)(2S)=43.1+/-3.4 MeV. Assuming that the eta(c) and eta(')(c) have equal branching fractions to K(S)Kpi, we obtain Gamma(gammagamma)(eta(')(c))=1.3+/-0.6 keV.
我们报告了在CLEO II/II.V数据13.6 fb⁻¹和CLEO III数据13.1 fb⁻¹中，通过双光子融合反应γγ→η′(c)→K⁰(S)K⁺⁻π⁻⁺对粲夸克偶素基态ηc(1(1)S0)的径向激发态η′(c)(2(1)S0)的观测结果。我们得到M(η′(c)) = 3642.9±3.1(统计)±1.5(系统) MeV以及M(ηc) = 2981.8±1.3(统计)±1.5(系统) MeV。1S0和3S1态之间超精细分裂的相应值为ΔM(hf)(1S) = 115.1±2.0 MeV以及ΔM(hf)(2S) = 43.1±3.4 MeV。假设ηc和η′(c)到K(S)Kπ的分支比相等，我们得到Γ(γγ)(η′(c)) = 1.3±0.6 keV。
