相关论文: Long-distant contribution and $\chi_{c1}$ radiativ…
We evaluate radiative decays of $\rho$ and $\omega$ going to two neutral mesons, $\pi^{0} \pi^{0}$ and $\pi^{0} \eta$. We use the sequential vector decay mechanisms in addition to chiral loops and $\rho$-$\omega$ mixing. The chiral loops…
We present a discussion of radiative decays $\chi_{cJ}\rightarrow\gamma \rho (\omega, \phi)$. The decay amplitudes are computed within the QCD factorisation framework. NRQCD has been used in the heavy meson sector as well as a collinear…
We apply perturbative QCD to the radiative decays of charmonia $J/\psi$ and $\chi_{cJ}$ into light mesons. We perform a complete numerical calculation for the quark-gluon loop diagrams involved in these processes. The calculated $J/\psi$…
In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay $B^0\to \chi_{c1} \pi^0$ with the light-cone QCD sum rules. The numerical results show that its contribution is rather large…
The decays $\chi_{cJ}\to\gamma V$ ($V=\phi, \rho^0, \omega$) are studied with a sample of radiative $\psip\to\gamma\chi_{cJ}$ events in a sample of $(1.06\pm0.04)\times 10^{8} \psip$ events collected with the BESIII detector. The branching…
We present our recent results for long-distance QCD effects in the FCNC radiative leptonic decays $B\to\gamma\ell^+\ell^-$, $\ell=\{e,\mu\}$. One encounters here two distinct types of long-distance effects: those encoded in the $B\to\gamma$…
The QCD radiative corrections to the leptonic decay rate of the $B_c$ meson are calculated using the formalism of nonrelativistic QCD (NRQCD) to separate short-distance and long-distance effects. The $B_c$ decay constant is factored into a…
A systematic approach to long-distance effects in exclusive radiative weak $B$ decays is presented, based on a combination of the heavy quark limit with perturbative QCD. The dominant long-distance effects, connected with weak annihilation…
Using a total of 2.74 x 10^7 decays of the psi(2S) collected with the CLEO-c detector, we present a study of chi_cJ -> gamma V, where V = rho^0, omega, phi. The transitions chi_c1 -> gamma rho^0 and chi_c1 -> gamma omega are observed with…
We consider the rare decay $\eta\to\pi^0\pi^0\gamma\gamma$ and calculate the non-resonant contribution to the amplitude to one loop in Chiral Perturbation Theory. We display our result as both a diphoton energy spectrum and a partial decay…
We calculate the predicted width for the radiative decay of a $1^{++}$ heavy meson via the channel $1^{++} \to 1^{--} +\gamma$ in the covariant light-front quark model. Specifically, we compute the decay widths for $\chi_{c1}(1P) \to J/\psi…
We study the radiative leptonic $B_c\to \gamma\ell\bar\nu$ decays in the nonrelativistic QCD effective field theory, and consider a fast-moving photon. As a result the interactions with the heavy quarks can be integrated out, and thus we…
Intermediate hadronic meson loop contributions to $J/\psi$, $\psi^\prime \to \gamma\eta_c$ ($\gamma\eta_c^\prime$) are studied apart from the dominant M1 transitions in an effective Lagrangian approach. Due to the property of the unique…
Utilizing $(2712.4 \pm 14.3) \times 10^6$ $\psi(3686)$ events collected with the BESIII detector at the BEPCII collider, we search for the hadronic transition process $\chi_{c1} \to \pi^+\pi^-\eta_c$ following the decay $\psi(3686)\to…
The radiative decay is believed to be an ideal lab to study hadronic structure of newly observed resonances because the reactions are governed by only the electromagnetic interaction (tree level). However, to obtain correct theoretical…
The hadronic decays of $\chi_{c1}\to VV$ and $\chi_{c2}\to VP$ are supposed to be suppressed by the helicity selection rule in the pQCD framework. With an effective Lagrangian method, we show that the intermediate charmed meson loops can…
We calculate long-distance contributions to the amplitudes A(K^0 --> pi pi, I) induced by the gluon and the electroweak penguin operators Q_6 and Q_8, respectively. We use the 1/N_c expansion within the effective chiral lagrangian for…
A previous model where the low-lying axial-vector mesons are dynamically generated, implementing unitarity in coupled channels in the vector-pseudoscalar ($VP$) meson interaction, is applied to evaluate the decay widths of the a_1(1260)$…
The weak radiative decay of $D^0\to V\gamma$ with $V=\bar{K}^0$, and $\phi$, $\rho^0$, and $\omega$, is systematically studied in the vector meson dominance (VMD) model. It allows us to distinguish the short-distance mechanisms which can be…
We investigate the long distance contribution via charmed hadron loops in the processes $\eta_c$, $\chi_{c0}$ and $h_c$ decaying to baryon anti-baryon pairs, which are supposed to be highly suppressed by the helicity selection rule as a…