Related papers: ${\mathcal O}(\alpha_s)$ corrections to $e^+e^-\ri…
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…
We investigate the ${\cal O}(\alpha_s)$ corrections to $e^+e^-\to J/\psi(\psi')+\chi_{cJ}$ ($J=0,1,2$) in the NRQCD factorization approach. These next-to-leading order (NLO) corrections are calculated at the level of helicity amplitude. We…
We investigate the ${\mathcal O}(\alpha_s v^2)$ correction to the $e^+e^-\to J/\psi+\eta_c$ process in the nonrelativistic QCD (NRQCD) factorization approach. Within some reasonable choices of the relative order-$v^2$ NRQCD matrix elements,…
Within the nonrelativistic QCD (NRQCD) factorization framework, we compute the long-awaited ${\mathcal O}(\alpha_s^2)$ correction for the exclusive double charmonium production process at $B$ factories, {\it i.e.}, $e^+e^-\to J/\psi+\eta_c$…
We analytically calculate the cross sections of double charmonium production in $e^+ e^- \to J/\psi(\psi(2S))\chi_{cJ}$ (J=0,1,2) at next-to-leading order (NLO) in $\alpha_s$ in nonrelativistic QCD, and confirm factorization of these…
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…
Within the nonrelativistic QCD (NRQCD) factorization framework, we have computed the ${\mathcal O}(\alpha_s^2)$ corrections to the exclusive production of $P$-wave spin-triplet charmonia $\chi_{cJ}(J=0,1,2)$ accompanied by a hard photon at…
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…
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…
We report the calculation of the process $e^+ e^- \to J/\psi J/\psi$ up to next-to-next-to-leading order (NNLO) at a center-of-mass (CM) energy of $\sqrt{s}=10.58$ GeV. We employ an improved NRQCD factorization approach, decomposing the…
The inclusive $J/\psi$ production in $e^+ e^- \to J/\psi c\bar c$ at B factories is one of the most challenging open problems in heavy quarkonium physics. The observed cross section of this double charm production process is larger than…
We calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to double charmonium production processes $e^+e^-\to\gamma^*\to\eta_c+h_c(1P)/\psi_{1,2}(1D)$ within the non-relativistic QCD (NRQCD) factorization…
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 review some recent progress in understanding various exclusive double charmonium production processes at $B$ factories, within the nonrelativistic QCD factorization framework. First we investigate the impact of the joint perturbative and…
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…
We calculate the relativistic correction to $J/\psi$ production in the color-singlet process $e^{+}e^{-}\to J/\psi+gg$ at B-factories. We employ the non-relativistic QCD (NRQCD) factorization approach, where the short-distance coefficients…
We present a new calculation, in the nonrelativistic QCD (NRQCD) factorization formalism, of the relativistic corrections to the double-charmonium cross section sigma[e+ e- -> J/psi+eta_c] at the energy of the Belle and BABAR experiments.…
One of the most challenging open problems in heavy quarkonium physics is the double charm production in $e^+e^-$ annihilation at B factories. The measured cross section of $e^+ e^- \to J/\psi + \eta_c$ is much larger than leading order (LO)…
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 calculate the next-to-leading-order (NLO) QCD correction to $e^+e^-\to J/\psi c \bar{c}$ at the B factories, and present theoretical predictions on the momentum and production angular distribution for $J/\psi$ production, and momentum…