Lattice study of $J/\psi \to \gamma {\eta }_c$ using a method without momentum extrapolation

Abstract

We present a model-independent method to calculate the radiative transition without the momentum extrapolation for the off-shell transition factors. The on-shell transition factor is directly obtained from the lattice hadronic function. We apply the method to calculate the charmonium radiative transition $J/\psi \to \gamma {\eta }_c$. After a continuous extrapolation under three lattice spacings, we obtain the on-shell transition factor as $V(0)=1.90(4)$, where the error is the statistical error that already takes into account the $a^2$-error in the continuous extrapolation. Finally, we determine the branching fraction of $J/\psi \to \gamma {\eta }_c$ as $\mathrm{Br}(J/\psi \to \gamma {\eta }_c)=2.49(11{)}_{\text{lat}}(5{)}_{\text{exp}}$, where the second error comes from the uncertainty of $J/\psi$ total decay width $92.6(1.7)$ keV.

arXiv comment10 pages, 8 figures, published in PRD

References in corpus (31)

• Aharonov-Bohm effect and nucleon-nucleon phase shifts on the lattice
• Radiative Transitions in Charmonium from Lattice QCD
• Light Meson Physics from Maximally Twisted Mass Lattice QCD
• Precision tests of the J/ψ from full lattice QCD: mass, leptonic width and radiative decay rate to η_c
• On the discretization of physical momenta in lattice QCD
• Number of $J/\psi$ events at BESIII
• Pseudoscalar decay constants of kaon and D-mesons from Nf=2 twisted mass Lattice QCD
• J/psi and psi(2S) Radiative Transitions to eta_c
• The low-lying baryon spectrum with two dynamical twisted mass fermions
• Average up/down, strange and charm quark masses with Nf=2 twisted mass lattice QCD
• Lattice QCD study of the radiative decays $J/\psi \to {\eta }_c\gamma$ and $h_c\to {\eta }_c\gamma$
• First-principles calculation of electroweak box diagrams from lattice QCD
• Charm annihilation effects on the hyperfine splitting in charmonium
• Radiative transitions in charmonium from $N_f=2$ twisted mass lattice QCD
• Lattice QCD calculation of the electroweak box diagrams for the kaon semileptonic decays
• Study of the pseudoscalar glueball in $J/\psi$ radiative decays
• Lattice QCD calculation of the pion charge radius using a model-independent method
• Observation of J/psi --> 3 gamma
• An estimate of the flavour singlet contributions to the hyperfine splitting in charmonium
• Contribution of disconnected diagrams to the hyperfine splitting of charmonium
• Measurement of $J/\psi \to \gamma {\eta }_{\mathrm{c}}$ decay rate and ${\eta }_{\mathrm{c}}$ parameters at KEDR
• Precise determination of decay rates for ${\eta }_c\to \gamma \gamma$, $J/\psi \to \gamma {\eta }_c$ and $J/\psi \to {\eta }_c{e}^{+}{e}^{-}$ from lattice QCD
• Lattice QCD calculation of the two-photon exchange contribution to the muonic-hydrogen Lamb shift
• Evidence for ${\eta }_c\to \gamma \gamma$ and Measurement of $J/\psi \to 3\gamma$
• First-principle calculation of ${\eta }_c\to 2\gamma$ decay width from lattice QCD
• Lattice QCD calculation of $K\to \ell {\nu }_{\ell }{\ell }^{\prime +}{\ell }^{\prime -}$ decay width
• Radiative Decay Width of $J/\psi \to \gamma {\eta }_{(2)}$ from $N_f=2$ Lattice QCD
• First lattice QCD calculation of $J/\psi$ semileptonic decay containing $D$ and $D_s$ particles
• Radiative Transitions in Charmonium from Lattice QCD
• A Lattice Study of the Two-photon Decay Widths for Scalar and Pseudo-scalar Charmonium
• Three Photon Decay of $J/\psi$ from Lattice QCD

Cited by in corpus (3)

• Observation of the charmonium decay ${\eta }_c\to \gamma \gamma$ in $J/\psi \to \gamma {\eta }_c$
• Study of the Magnetic Dipole Transition of $J/\psi \to \gamma {\eta }_c$ via ${\eta }_c\to p\bar{p}$
• Lattice determination of the neutrino background for $J/\psi \to \gamma +\text{invisible}$