Related papers: Relativistic correction to $e^{+}e^{-}\to J/\psi+g…
The failure of observing the $e^+ e^- \to J/\psi+J/\psi$ events at $B$ factories to date is often attributed to the significant negative order-$\alpha_s$ correction. In this work we compute the ${\cal O}(\alpha^2_s)$ correction to this…
As a test of the color-singlet mechanism of the nonrelativistic QCD (NRQCD) factorization approach, we consider the exclusive two-quarkonium productions in electron-positron annihilation e+ e- -> eta_c + gamma and e+ e- -> J/psi + J/psi at…
The production cross sections of $e^+e^- $ to a heavy quarkonium with $C$-parity even $S-$wave and $P-$wave associated with a photon are analyzed in the framework of non-relativistic Quantum Chromodynamics(NRQCD) factorization formalism.…
We analyse the structure of relativistic corrections in the inclusive production of polarized $J/\Psi$ from b-quark decay. The analysis is performed not only for the production channel in which the $c\bar c$ pair is a color sinlet, but also…
We study leptoproduction of $J/\psi$ at large $Q^2$ within the nonrelativistic QCD (NRQCD) factorization formalism. The cross section is dominated by color-octet terms that are of order $\alpha_s$. The color-singlet term, which is of order…
In this work, we calculate the next-to-leading-order (NLO) QCD corrections to the process $p+p \to J/\psi + \gamma$ via the color-singlet mechanism at the LHC. The results show that the partial cross section ($p_t^{J/\psi}>$3GeV and…
Recent observations of the J/psi spectrum produced in e^+e^- collisions at the Upsilon(4S) resonance are in conflict with fixed-order calculations using Non-Relativsitic QCD effective theory (NRQCD). One problem is an enhancement in the…
We investigate the ${\cal O}(\alpha_s)$ correction to $e^+e^-\to J/\psi+\eta_{c2}$ in the NRQCD factorization approach. A detailed comparative study between $e^+e^-\to J/\psi+\eta_{c2}$ and $e^+e^-\to J/\psi+\chi^\prime_{c1}$ at $B$ factory…
We compute the relativistic corrections to the color-singlet contribution to gluon fragmentation into a J/psi at relative order v^4, making use of the nonrelativistic QCD (NRQCD) factorization approach. The corresponding full-QCD process…
In this paper, we study the next-to-next-to-leading-order (NNLO) QCD corrections for the process $e^+e^- \to J/\psi+J/\psi$ at the $B$ factories. By including the NNLO corrections, the cross section turns negative due to the poor…
Based on the nonrelativistic QCD factorization approach, ${\mathcal O}(\alpha_s v^2)$ corrections to $\jpsi$ plus $\eta_c$ production in $e^+e^-$ annihilation at $\sqrt{s}=10.6 \gev$ is calculated in this work. The numerical results show…
We compute the ${\mathcal O}(\alpha_s^2)$ corrections to the exclusive channels $e^+e^-\to J/\psi+\chi_{cJ}$ ($J=0,1,2$) at $\sqrt{s}=10.58$ GeV within the nonrelativistic QCD (NRQCD) factorization framework. The validity of NRQCD…
Non-relativistic QCD (NRQCD) is used to calculate the relativistic correction to the amplitude for exclusive photoproduction of vector Quarkonia in the near-threshold region within the generalized parton distribution (GPD) framework. The…
In nonrelativistic QCD (NRQCD), we study $e^+ e^- \to J/\psi(\psi(2S)) +\chi_{c0}$ at $B$ factories, where the P-wave state $\chi_{c0}$ is associated with an S-wave state $J/\psi$ or $\psi(2S)$. In contrast to the failure of factorization…
Within the framework of nonrelativistic-QCD factorization, we calculate both the next-to-leading-order relativistic and QCD corrections to prompt $J/\psi$ pair production, with feeddown from $\psi(2S)$ mesons, via photon-photon collisions…
Using the nonrelativistic QCD(NRQCD) factorization formalism, we calculate the color-singlet cross sections for exclusive production processes ${e^++e^-\to J/\psi+\eta_c}$~ and ~$e^++e^-\to J/\psi + \chi_{cJ}$~$(J=0,1,2)$ at the…
Next-to-Leading-Order(NLO) QCD corrections to double J/psi production in e^+e^- annihilation at sqrt{s}=10.6 GeV are calculated. We find that they greatly decrease the cross section, with a K factor (NLO/LO) ranging from -0.31 to 0.25…
We investigate the processes $e^+e^-\to \eta_c+\gamma$ and $e^+e^-\to \chi_{cJ}+\gamma$ at B factories within the NRQCD factorization framework, computing the corresponding helicity amplitudes through $\mathcal{O}(\alpha_s^2)$. The…
We calculate the cross sections of inclusive J/psi production in photoproduction and two-photon scattering, involving both direct and resolved photons, and in e^+e^- annihilation at next-to-leading order (NLO) within the factorization…
Next-to-Leading-Order(NLO) QCD corrections to J/jpsi plus eta_c production in e+e- annihilation at sqrt{s}=10.6 GeV is calculated in this paper, and an analytic result is obtained. By choosing proper physical parameters, a K factor (ratio…