Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production via two-photon collisions

Abstract

We report the measurement of gamma gamma to eta_c(1S), eta_c(2S) to eta' pi+ pi- with eta' decays to gamma rho and eta pi+ pi- using 941 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The eta_c(1S) mass and width are measured to be M = [2984.6\pm0.7 (stat.)\pm2.2 (syst.)] MeV/c^{2} and Γ= [30.8^{+2.3}_{-2.2}~(stat.) \pm 2.5~(syst.)] MeV, respectively. First observation of eta_c(2S) to eta' pi+ pi- with a significance of 5.5sigma including systematic error is obtained, and the eta_c(2S) mass is measured to be M = [3635.1\pm3.7~(stat.)\pm2.9~(syst.)] MeV/c^{2}. The products of the two-photon decay width and branching fraction (B) of decays to eta'pi+ pi- are determined to be Γ_{gamma gamma}B = [65.4\pm2.6~(stat.)\pm6.9~(syst.)] eV for eta_c(1S) and [5.6^{+1.2}_{-1.1}~(stat.)\pm1.1~(syst.)] eV for eta_c(2S). A new decay mode for the eta_c(1S) to eta'f_0(2080) with f_0(2080) to pi+ pi- is observed with a statistical significance of 20sigma. The f_0(2080) mass and width are determined to be M = [2083^{+63}_{-66}~(stat.)\pm 32~(syst.)] MeV/c^{2} and Γ= [178^{+60}_{-178}~(stat.) \pm 55~(syst.)] MeV. The cross sections for gamma gamma to eta' pi+ pi- and eta'f_{2}(1270) are measured for the first time.

arXiv comment19 pages, 14 figures

References in corpus (21)

• Heavy quarkonium: progress, puzzles, and opportunities
• Effective field theories for heavy quarkonium
• The Physics of the B Factories
• Two-Photon Decays of Mesons in a Relativistic Quark Model
• Observation of eta_c^{prime} Production in gamma gamma Fusion at CLEO
• Two-photon decay rates of heavy quarkonia in the relativistic quark model
• Study of ${\pi }^0$ pair production in single-tag two-photon collisions
• The handbag contribution to gamma gamma to pi pi and K K
• Study of $\psi (3686)\to {\pi }^0{h}_c,h_c\to \gamma {\eta }_c$ via ${\eta }_c$ exclusive decays
• Annihilation Rate of Heavy $0^{-+}$ Quarkonium in Relativistic Salpeter Method
• High-statistics study of K^0_S pair production in two-photon collisions
• Two-photon width of eta_c and eta'_c from Heavy-Quark Spin Symmetry
• Study of B-meson decays to eta_c K^(*), eta_c(2S) K^(*) and eta_c gamma K^(*)
• Study of charmonia in four-meson final states produced in two-photon collisions
• Study of B^{+-} -> K^{+-}(K_S K pi)^0 Decay and Determination of eta_c and eta_c(2S) Parameters
• Pseuduscalar Heavy Quarkonium Decays With Both Relativistic and QCD Radiative Corrections
• Observation of eta_c(1S) and eta_c(2S) decays to K+ K- pi+ pi- pi0 in two-photon interactions
• The Decay ${\eta }_c\to \gamma \gamma$ : A Test for Potential Models
• First study of η_c, η(1760) and X(1835) production via η'π^+π^- final states in two-photon collisions
• Prospects for detecting an ${\eta }_c^{\prime }$ in two photon processes
• Two-photon decay of pseudoscalar quarkonia

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