Related papers: Inclusive Radiative psi(2S) Decays
The branching ratio of J/psi-->K_S K_L is measured with improved precision to be B(J/psi-->K_S K_L) = (1.82\pm 0.04\pm 0.13)\times 10^{-4}. using J/psi data collected with the Beijing Spectrometer (BESII) at the Beijing Electron-Positron…
The decay $B_c^+ \to \psi(2S)\pi^+$ with $\psi(2S) \to \mu^+\mu^-$ is observed with a significance of $5.2\,\sigma$ using $pp$ collision data corresponding to an integrated luminosity of $1.0\,\invfb$ collected by the LHCb experiment. The…
Motivated by concerns regarding possible two-body contributions to the recently-measured inclusive Upsilon(nS)->gamma+X (n=1, 2, 3) direct photon spectra, we report on a new study of exclusive radiative decays of these narrow Upsilon(nS)…
The branching ratio in the charged-pion kinetic energy region of 55 to 90 MeV for the direct photon emission in the K- --> pi- pi0 gamma decay has been measured using in-flight decays detected with the ISTRA+ setup operating in the 25 GeV/c…
We report the observation of $\Upsilon(2S)\to\gamma\eta_{b}(1S)$ decay based on analysis of the inclusive photon spectrum of $24.7$ fb$^{-1}$ of $e^+ e^-$ collisions at the $\Upsilon(2S)$ center-of-mass energy collected with the Belle…
We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and…
We searched for the $\mu^+\mu^-$ decay of a light vector gauge boson, also known as dark photon, in the $e^+ e^- \to \mu^+ \mu^- \gamma_{\rm ISR}$ process by means of the Initial State Radiation (ISR) method. We used 1.93~fb$^{-1}$ of data…
We present a study of the inclusive photon spectra from 5.9 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c width and mass.…
The radiative decay $K^+ \to \pi^+ \pi^0 \gamma$ ($K_{\pi 2 \gamma}$) has been measured with stopped positive kaons. A $K_{\pi 2 \gamma}$ sample containing 4k events was analyzed, and the $K_{\pi 2 \gamma}$ branching ratio of the direct…
Motivated by concerns regarding possible two-body contributions to the recently-measured inclusive $\Upsilon$(nS)$\to\gamma+X$ direct photon spectrum, we report on a preliminary new study of exclusive radiative decays of the $\Upsilon$…
The ratio R_{\eta}=\Gamma(\eta -> \pi^+\pi^-\gamma)/\Gamma(\eta -> \pi^+\pi^-\pi^0) has been measured by analyzing 22 million \phi \to \eta \gamma decays collected by the KLOE experiment at DA\PhiNE, corresponding to an integrated…
In this note we comment on a recent publication in this journal by the CERES (NA45) Collaboration. The authors report to have determined an upper limit on the direct photon yield relative to the decay photon yield in S+Au collisions of 14 %…
Using a sample of 2.59 x 10^7$ psi(2S) decays collected by the CLEO--c detector, we present results of a search for the decay chain psi(2S) -> pi^0 h_c, h_c -> n(pi^+ pi^-) pi^0, n=1,2,3. We observe no significant signals for n=1 and n=3…
We study the photon spectrum in the radiative decays of the charmonium $\frac{1}{\Gamma}\frac{d\Gamma (J/\psi\rightarrow\gamma gg)}{dz}$ as an excellent scene for hunting the exotic mesons (hybrids $q\bar{q}g$ and glueballs $gg$) and an…
We report a search for the decay psi(2S) -> gamma eta_c(2S) in a sample of 25.9 million psi(2S) events collected with the CLEO-c detector. No signals are observed in any of the 11 exclusive eta_c(2S) decay modes studied, or in their sum.…
e+e- Experiments producing charmonium are reviewed. It is found that the contribution of the continuum amplitude via virtual photon was neglected in almost all the experiments and the channels analyzed. It is shown that the contribution of…
The decay $B_c\rightarrow J/\psi K^+ K^- \pi^+$ is observed for the first time, using proton-proton collisions collected with the LHCb detector corresponding to an integrated luminosity of 3fb$^{-1}$. A signal yield of $78\pm14$ decays is…
Using the inclusive photon spectrum based on a data sample collected at the $J/\psi$ peak with the KEDR detector at the VEPP-4M $e^+e^-$ collider, we measured the rate of the radiative decay $J/\psi\to\gamma\eta_{\rm c}$ as well as…
While measuring the ratio R_K = \Gamma(K+e2(\gamma))/\Gamma(K+\mu2(\gamma)), the KLOE Collaboration has studied the radiative process Ke2\gamma. The ratio of the width for the Ke2\gamma decay with a positively polarized photon from…
We have searched for the decay Ks->3p^0 with the KLOE experiment at DAFNE using data from e^+ e^- collisions at a center of mass energy W= m(phi) for an integrated luminosity L=450 pb^-1. The search has been performed with a pure Ks beam…