Related papers: Two Photon Width of eta_c (paper version)
We discuss the measured partial width of the pseudoscalar charmonium state, $\eta_c$, into two photons. Predictions from potential models are examined and compared with experimental values. Including radiative corrections, it is found that…
We discuss the partial width of the pseudoscalar charmonium state eta_c and bottomonium state eta_b into two photons. Predictions from potential models are examined and compared with experimental values for the eta_c case. Through the NRQCD…
We discuss the theoretical predictions for the two photon decay width of the pseudoscalar etab meson. Predictions from potential models are examined. It is found that various models are in good agreement with each other. Results for etab…
Using 13.4 $fb^{-1}$ of data collected with the CLEO detector at the Cornell Electron Storage Ring, we have observed 300 events for the two-photon production of ground-state pseudo-scalar charmonium in the decay $\eta_c$ -> $K_S K^{\mp}…
We discuss the theoretical predictions for the two photon decay width of the pseudoscalar etab meson. Predictions from potential models are examined. It is found that various models are in good agreement with each other. Results for etab…
We report on our recent evaluation of the two-photon width of the pseudoscalar quarkonia, eta_c(nS) and eta_b(nS) in an approach based on Heavy-Quark Spin Symmetry (HQSS). To what concerns the 1S state eta_c, our parameter-free computation…
Recent BABAR results on two-photon processes are presented. A high statistics study of the two-photon production of the charmonium states eta_c and eta_c(2S) is performed. The mass and width of eta_c and eta_c(2S) are measured; the ratio of…
We evaluate the two-photon width of the pseudoscalar charmonia, Gamma(eta_c -> gamma gamma) and Gamma(eta'_c -> gamma gamma), within a Heavy-Quark Spin-Symmetry setting and show that whereas the former agrees with experiment, the latter is…
The mass and total width of the eta_c meson have been measured in two-photon interactions at the SLAC asymmetric B-Factory with the BABAR detector. With a sample of approximately 2500 reconstructed eta_c -> Ks K pi decays in 88 fb-1 of…
In this exploratory study, two photon decay widths of pseudo-scalar ($\eta_c$) and scalar ($\chi_{c0}$) charmonium are computed using two ensembles of $N_f=2$ twisted mass lattice QCD gauge configurations. The simulation is performed two…
We present an exploratory lattice study for the two-photon decay of $\eta_c$ using $N_f=2$ twisted mass lattice QCD gauge configurations generated by the European Twisted Mass Collaboration. Two different lattice spacings of $a=0.067$fm and…
Feasibility of a measurement of the partial decay width of the intermediate-mass Higgs boson into two photons at a photon-photon collider is studied by a simulation. The QCD radiative correction for quark pair background processes is taken…
The two-photon width of chi_c2 (^3P_2) state of charmonium has been measured using 14.4 fb^-1 of e+e- data taken at sqrt{s} = 9.46-11.30 GeV with the CLEO III detector. The two-photon fusion reaction studied is e+e- -> e+e- gamma gamma,…
The relation between the ratio Gamma_{ee}(psi')/Gamma_{ee}(J/psi) and Gamma_{2gamma}(eta_{c}')/Gamma_{2gamma}(eta_{c}), expressed in terms of the configuration mixing amplitudes induced by the contact spin-spin interaction of quarks in the…
We predict the two-photon width of the pseudoscalar bottomonia, Gamma(eta_b -> gamma gamma), Gamma(eta'_b -> gamma gamma) and Gamma(eta''_b -> gamma gamma) within a Heavy-Quark Spin-Symmetry setting following the same line as our recent…
The two-photon width $\Gamma_{\gamma\gamma}$ of the $\eta_c$ meson has been measured with the L3 detector at LEP. The $\eta_c$ is studied in the decay modes $\pi^+\pi^-\pi^+\pi^-$, $\pi^+\pi^-$K$^+$K$^-$, K$_s^0$K$^\pm\pi^\mp$,…
With the recent measurements on $\eta_{c}$ and $\eta_{c}^{\prime}$ at CLEO, Babar and Belle, and with the prospect of finding the $\eta_{b}$ at the Tevatron, it seems appropriate to have another look at the two-photon decay of heavy…
By analyzing existing data on pseudoscalar charmonium decays, we obtain the ratio of the branching fractions of $\eta_c(2S)$ and $\eta_c$ decays into ten different final states with light hadrons. For the first time, we test the two…
Using a data sample of 24.5 million psi(2S) the reactions psi(2S)->gamma chi_cJ, chi_cJ->gamma gamma have been studied for the first time to determine the two-photon widths of the chi_cJ states of charmonium in their decay into two photons.…
Using the CLEO-II detector at the CESR $e^+e^-$ storage ring running at the center-of-mass energy around 10.6 GeV, we have studied exclusive production of charmonium states in two-photon collisions. Employing a dataset comprising 3.0 ${\rm…