Related papers: Lattice study of $J/\psi \rightarrow \gamma\eta_c$…
We present a study for charmonium radiative transitions: $J/\psi\rightarrow\eta_c\gamma$, $\chi_{c0}\rightarrow J/\Psi\gamma$ and $h_c\rightarrow\eta_c\gamma$ using $N_f=2$ twisted mass lattice QCD gauge configurations. The single-quark…
We compute the hadronic matrix element relevant to the physical radiative decay $\eta_{c}(2S)\to J/\psi\gamma$ by means of lattice QCD. We use the (maximally) twisted mass QCD action with Nf=2 light dynamical quarks and from the…
We calculate the J/{\psi} mass, leptonic width and radiative decay rate to \gamma \eta_c from lattice QCD including u, d and s quarks in the sea for the first time. We use the Highly Improved Staggered Quark formalism and nonperturbatively…
We present the results of our lattice QCD study of the hadronic matrix elements relevant to the physical radiative J/psi -> eta_c gamma and hc -> eta_c gamma decays. From computations with Nf=2 dynamical quark in twisted mass QCD at four…
We report on the computation of amplitudes describing the radiative decay processes $J/\psi \to \gamma \, \eta$ and $J/\psi \to \gamma \, \eta'$ from first principles via lattice QCD. Using lattices with two degenerate flavors of light…
We present the results of our lattice QCD study of the hadronic matrix elements relevant to the physical radiative $J/\psi\to \eta_c\gamma$ and $h_c\to \eta_c\gamma$ decays. We used the twisted mass QCD action with $N_{\rm f}=2$ light…
We propose a direct method to calculate the decay width of a hadron decaying to two photons, which is conventionally obtained by an extrapolation for various off-shell form factors. The new method provides an simple way to examine the…
We perform a lattice QCD calculation of the $\eta_c\to2\gamma$ decay width using a model-independent method that requires no momentum extrapolation of the off-shell form factors. This method also provides a straightforward and simple way to…
At present, there are many experimental and theoretical results for $J/\psi\rightarrow\eta_{c}+\gamma$ process, while the results are inconsistent based on different methods and considerations. In this paper, the light cone sum rules method…
Estimating decay parameters in lattice simulations is a computationally demanding problem, requiring several volumes and momenta. We explore an alternative approach, where the transition amplitude can be extracted from the spectral…
The form factors in the radiative decay of $J/\psi$ to a scalar glueball are studied within quenched lattice QCD on anisotropic lattices. The continuum extrapolation is carried out by using two different lattice spacings. With the results…
By using a 2.92 fb$^{-1}$ data sample taken at $\sqrt{s} = 3.773$ GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions $\psi(3770)\to\gamma\eta_c$ and $\gamma\eta_c(2S)$ through the hadronic…
In this work, we present the first lattice QCD study on the invisible decay $J/\psi \rightarrow \gamma\nu\bar{\nu}$. The calculation is accomplished using $N_f=2$ twisted mass fermion ensembles. The excited-state effects are observed and…
Radiative transitions between charmonium states offer an insight into the internal structure of heavy-quark bound states within QCD. We compute, for the first time within lattice QCD, the transition form-factors of various multipolarities…
We calculate the leading-order matrix element for exclusive decays of $b \to s\gamma$ in the quenched approximation of lattice QCD on a $24^3\times48$ lattice at $\beta=6.2$, using an O(a)-improved fermion action. The matrix element is used…
We present a first principles calculation within quantum chromodynamics (QCD) of the radiative decays of the $J/\psi$ into the light pseudoscalar mesons $\eta$ and $\eta'$. Within a lattice computation we obtain the transition form-factors…
The LHC$_b$ collaboration has systematically measured the rates of $B_c\to J/\psi K$, $B_c\to J/\psi D_s$, $B_c\to J/\psi D_s^*$ and $B_c\to \psi(2S) \pi$. The new data enable us to study relevant theoretical models and further determine…
The coupling of various charmonium mesons to a photon is studied using lattice QCD, giving access to radiative form factors and transitions, and probing the mesons' structure. Methods are developed which allow the robust determination of…
Preliminary results are presented on the calculation of the relevant form factor for the radiative decay $\overline{B} \rightarrow K^* \gamma$ We find that the form factor is weakly dependent on the spectator quark mass. We compare the…
We perform a lattice QCD calculation of the $\chi_{c0} \rightarrow 2\gamma$ decay width using a model-independent method which does not require a momentum extrapolation of the corresponding off-shell form factors. The simulation is…