相关论文: M2 signatures in psi(2S) radiative decays

Using 24 million $\psi' \equiv \psi(2S)$ decays in CLEO-c, we have searched for higher multipole admixtures in electric-dipole-dominated radiative transitions in charmonia. We find good agreement between our data and theoretical predictions…

We have studied the inclusive photon spectrum in psi(2S) decays using the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates for psi(2S)--> gamma chicJ(1P) (J=0,1,2). We also confirm…

Using $106\times10^6$ $\psi(2S)$ events collected with the BESIII detector at the BEPCII storage ring, the higher-order multipole amplitudes in the radiative transition $\psi(2S)\to\gamma\chi_{c2}\to\gamma\pi\pi/\gamma KK$ are measured. A…

The polarization of the chi_{c2} produced in psi(2S) decays into gamma chi_{c2} is measured using a sample of 14*10^6 psi(2S) events collected by BESII at the BEPC. A fit to the chi_{c2} production and decay angular distributions in psi(2S)…

Using 24.5 million psi(2S) decays collected with the CLEO-c detector at CESR we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)->gamma eta_c) = (4.32+/-0.16+/-0.60)x10^-3,…

We report determination of branching fractions for the decays psi(2S) --> h + J/psi, where h=any, pi+pi-, pi0pi0, eta, pi0, and gamma gamma through chi_{c0,1,2}. These measurements use 27M psi(2S) decays produced in e+e- collision data…

Using 14 million psi(2S) events accumulated at the BESII detector, we report first measurements of branching fractions or upper limits for psi(2S) decays into gamma ppbar, gamma 2(pi^+pi^-), gamma K_s K^-pi^++c.c., gamma K^+ K^- pi^+pi^-,…

Using 106~million $\psi(3686)$ events collected with the BESIII detector, we measure multipole amplitudes for the decay $\psi(3686)\rightarrow\gamma\chi_{c1,2}\to\gamma\gamma J/\psi$ beyond the dominant electric-dipole amplitudes. The…

Using photon conversions to e^+e^- pairs, the energy spectrum of inclusive photons from psi(2S) radiative decays is measured by BESII at the Beijing Electron-Positron Collider. The chi_{cJ}(1P) states (J=0,1,2) are clearly observed with…

The strong and the electromagnetic amplitudes are analyzed on the basis of the measurements of J/psi, psi(2S) -> 1-0- in e+e- experiments. The currently available experimental information is revised with inclusion of the contribution from…

Using $\gamma \gamma J/\psi, J/\psi \ra e^+ e^-$ and $\mu^+ \mu^-$ events from a sample of $14.0\times 10^6$ $\psip$ decays collected with the BESII detector, the branching fractions for $\psip\ra \pi^0\J$, $\eta\J$, and…

With a sample of 14 million psi(2S) events collected by the BESII detector at the Beijing Electron Positron Collider (BEPC), the decay channels psi(2S)->p p-bar, Lambda Lambda-bar, Sigma0 Sigma0-bar, Xi Xi-bar are measured, and their…

The BES Collaboration has measured $\Psi(2S)$ decay to $J/\Psi \pi^+\pi^-$. Using the mixed hybrid theory for the $\Psi(2S)$ we estimate the decay to $J/\Psi(1S)$ + $\sigma$. Using the known $\sigma \rightarrow 2\pi$ coupling constant, we…

The BES Collaboration has measured $\Psi(2S)$ decay to $J/\Psi \pi^+\pi^-$. Using the mixed hybrid theory for the $\Psi(2S)$ we estimate the decay to $J/\Psi(1S)$ + $\sigma$. Using the known $\sigma \rightarrow 2\pi$ coupling constant, we…

The radiative decays of the B mesons may have a significant contribution from the transition b -> s J/psi followed by the J/psi-photon conversion. The size of this contribution is re-analysed in the light of a phenomenological model for the…

We have studied the inclusive photon spectra in Upsilon(2S) and \Upsilon(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition…

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 $\eta_c(1S)$;…

The radiative decay $\Sigma_Q^* \rightarrow \Lambda_Q\gamma$ can have both magnetic dipole (M1) and electric quadrupole (E2) components. In the heavy quark limit $M_Q\rightarrow\infty$ the transition arises from the spin of the light…

Tagged linearly polarized photons have been used at the Mainz Microtron MAMI for simultaneous measurements of the p(\vec{\gamma},p)\pi^0 and p(\vec{\gamma},\pi^+)n reaction channels to study the \gamma N \to \Delta(1232) transition. The…

The angular distributions of the decay products in the successive decays chi_c (chi_b) to J/psi (Upsilon) gamma and J/psi (Upsilon) to l+l- are calculated as a function of the angular momentum composition of the decaying chi meson and of…