Related papers: Recent BABAR Results on Two-photon Physics
Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were…
We present several recent results from the BaBar collaboration in the areas of initial state radiation physics and transition form factors. An updated study of the processes e+e- -> K+K-pi+pi- and e+e- -> K+K-pi0pi0 provides an improved…
Measurements of branching fractions for nine different final states, based on a data sample of approximately 4 million psi(2S) events collected with the BESI detector at the BEPC, are reported. Using the same event sample, radiative decays…
Experiments that study the photoproduction of pseudoscalar mesons; pions, etas and kaons, have the potential to increase our knowledge of baryon and hyperon resonance properties. Recent experiments at JLab, Mainz, GRAAL, and Bonn are…
Using 22.7 million BBbar events recorded with the BABAR detector, the inclusive branching fractions for the production of J/psi, psi(2S) and Chi_c in B decays are presented. Combining the charmonium state with a K+-, K0, K*+-, K*0 or…
We study the processes $\gamma \gamma \to K^0_S K^{\pm}\pi^{\mp}$ and $\gamma \gamma \to K^+ K^- \pi^0$ using a data sample of 519~$fb^{-1}$ recorded with the BaBar detector operating at the SLAC PEP-II asymmetric-energy $e^+ e^-$ collider…
This review briefly outlines recent experimental results from the charmonium system. These include new measurements of the M1 radiative transition rates $B(\psi(1S,2S)\to\gamma\eta_c(1S))$; new insights into the mass of the $\eta_c(1S)$;…
We evaluate the $\pi^0\gamma^* \to \gamma$ transition form factor and $\gamma\gamma$ decay widths for $\pi^0, \eta_c$ and $\eta_b$ treated as $q\bar{q}$ bound states in the Bethe-Salpeter formalism, incorporating the dynamical chiral…
Using 12.7 $fb^{-1}$ of data collected with the CLEO detector at CESR, we observed two-photon production of the $c \bar c$ states $\chi_{c0}$ and $\chi_{c2}$ in their decay to $\pi^+ \pi^- \pi^+ \pi^-$. We measured…
We present preliminary results on the measurement of the I=1/2 $K \pi$ $\mathcal{S}$-wave through a model independent partial wave analysis of $\eta_c$ decays to $K^0_S K^+ \pi^-$ and $K^+ K^- \pi^0$ produced in two-photon interactions. We…
The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the first time using a sample of 5.8X10^7 J/\psi events collected by the BESII detector. The product branching fractions are determined to be B(J/\psi-->gamma…
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,…
One of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic. The $BABAR$ experiment has extensively studied those in B…
We study the processes $\gamma \gamma \to K^+ K^- \eta$ and $\gamma \gamma \to K^+ K^- \pi^0$ using a data sample of 519 $fb^{-1}$ recorded with the BaBar detector operating at the SLAC PEP-II asymmetric-energy $e^+ e^-$ collider at…
We have developed a phenomenological approach which describes very well the pi0, eta and eta-prime meson production in the two-photon interactions. The simultaneous description of the pi0, eta and eta-prime meson two-photon form factors is…
The two photon transition of $\bar{c}c$ quarkonia are studied within a covariant approach based on the consistent truncation scheme of the quantum chromodynamics Dyson-Schwinger equation for the quark propagator and the Bethe--Salpeter…
By means of the universal unitary and analytic model of electromagnetic structure of hadrons the two-photon decay rates of P=pi^0, eta, eta' mesons are determined in an alternative way from data on their transition form factors.
The form factors for the transitions pi-photon, eta-photon, eta'-photon and etac-photon are analyzed within the modified perturbative approach in which quark transverse degrees of freedom are retained. The results for the form factors are…
We present an analysis of the recent measurement of $\eta'$-meson production by two virtual photons made by BaBar collaboration. It is the first measurement of a transition form factor which is entirely within the kinematic regime of the…
The eta_c-gamma transition form factor is calculated in a model based on a modified hard scattering approach to exclusive reactions, in which transverse degrees of freedom are taken into account. For the eta_c-meson a distribution amplitude…