Related papers: Two photon width of heavy pseudoscalar mesons
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 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 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 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…
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}…
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 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…
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…
A search for the pseudoscalar meson eta_b was performed at LEP~II energies with an integrated luminosity of 700pb^-1. The search, done for the decay modes into 4 and 6 charged particles yielded 0 and 1 candidates, respectively. Upper limits…
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$^\pm\pi^\mp$,…
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…
A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breakdown in Upsilon leptonic decays. Moreover, the mixing between such a pseudoscalar Higgs and $\eta_b$ states might shift the mass levels…
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…
Within the framework of nonrelativistic QCD (NRQCD) factorization formalism, we compute the helicity amplitude as well as the decay width of $\eta_{Q2}$ ($Q=c,b$) electromagnetic decay into two photons up to next-to-next-to-leading order…
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 the first observation of the bottomonium ground state eta_b(1S) in the photon energy spectrum using a sample of 109+/-1 million of Upsilon(3S) events recorded at the Upsilon(3S) energy with the BaBar detector at the PEP-II B…
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…
We calculate the decay rate B-> X_s photon photon via intermediate psuedoscalar charmonium eta_c. This process is thought to be the main long-distance contribution which dominates the corresponding inclusive rare B decay. We point out that…