相关论文: Double charmonium productions in electron-positron…

In this work we study the process $e^{+}+e^{-}\longrightarrow J/\Psi+\eta_{c} $ at energy $\sqrt{s}= 10.6 GeV$ observed recently at B-factories whose measurements were made by Babar and Belle groups. We calculate the cross section for this…

In this work we evaluate the cross section of the process $e^+e^-\to J/\psi \eta_c$ at energy $\sqrt{s}\approx 10.6$ GeV in the Bethe-Salpeter formalism. To simplify our calculation, the heavy quark limit is employed. Without taking the…

In present work we study the production of ground and excited charmonium pairs in $e^- e^+ \rightarrow \Psi(nS)+ \chi_{cJ}(nP)$ for $J=0,1$ and $n=1,2$, through leading order (LO) tree-level diagrams $\sim O(\alpha_{em} \alpha_s)$, which…

We study the processes, $e^- e^+ \rightarrow \gamma^* \gamma^* \rightarrow J/\psi +J/\psi$, and $e^- e^+ \rightarrow \gamma^* \gamma^* \rightarrow \eta_c+ \eta_c$ at $\sqrt{s}=10.6$ GeV in the framework of $4\times 4$ Bethe-Salpeter…

Recent measurements of the Belle Collaboration of the exclusive production of two charmonia in the $e^+e^-$ annihilation differ substantially from theoretical predictions. Recently it was suggested that a significant part of this…

We present a new analysis of double charmonium production in e^+ e^- annihilation. The observation of the processes e^+ e^- -> J/psi eta_c, J/psi chi_c0, and J/psi eta_c(2S) is confirmed using a dataset more than three times larger than…

In present work we study the production of ground and excited charmonium states in $e^- e^+ \rightarrow \gamma\chi_{cJ}(nP)(J=0,1)$, and $e^- e^+ \rightarrow \gamma \eta_c(nS)$, through leading order (LO) diagrams, which proceed through…

We calculate the exclusive cross sections for e^+ e^- annihilation into two charmonium states through a virtual photon. Purely electromagnetic contributions are surprisingly large, changing the cross sections by as much as 21%. The…

In this paper initial state radiation corrections to double production of charmonium mesons on one-photon electron-positron annihilation at center of mass energy $\sqrt{s}=10.6\GeV$ are studied. It is shown, that these corrections have…

We calculate cross sections of a pair $B_c$ meson production on the basis of two-photon mechanism from electron-positron annihilation. We investigate the production cross sections in nonrelativistic approximation and with the account of…

We review the charmonium production in $e^+e^-$ annihilation at $\sqrt{s}=10.6GeV$. NRQCD predictions for the $J/\psi$ production are compared with the recent measurements by BaBar and Belle. A NRQCD calculation for the $D$-wave charmonium…

We calculate the contributions from QED processes involving two virtual photons to the cross sections for e^+ e^- annihilation into two charmonium states with the same C-parity. Generically, the cross sections are three orders of magnitude…

In this paper we study inclusive production of vector charmonium states $J/\psi$ or $\psi(2S)$ in two-photon $\epem$-annihilation at $\sqrt s=10.6 \rm GeV$ using color-singlet model. Analytic expressions for differential cross sections,…

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…

We suggest searching for excited charmonium states in $e^+e^-$ annihilation via double charmonium production at $\sqrt{s}=10.6$ GeV with $B$ factories, based on a more complete leading order calculation including both QCD and QED…

We study the production of $J/\psi+c\bar{c}$ in $e^+e^-$ annihilation through two virtual photons. The cross section is estimated to be 23 fb at $\sqrt{s}=10.6$ GeV, which is smaller by a factor of six than the calculated cross section for…

We consider the production of charmonium by $D\bar D$ annihilation during the mixed and hadronic phase of Pb-Pb collision at LHC energy. The calculations for secondary $J/\psi$ and $\psi^,$ production are performed within a kinetic model…

Motivated by the recent observation of double charm quark pair production by the Belle Collaboration, we calculate the complete ${\cal O}(\alpha_{s}^{2})$ inclusive production cross sections for $\eta_{c}$, $J/\psi$, and $\chi_{cJ}$(J=0, 1,…

The ALICE Collaboration at the LHC has measured the J/$\psi$ and $\psi^{'}$ photoproduction at mid-rapidity in ultra-peripheral Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV. The charmonium is identified via its leptonic decay for events…

We measure the cross section of $e^+e^-\rightarrow\eta_c J/\psi$ at the $\Upsilon(nS) (n=1$ -- $5)$ on-resonance and 10.52 GeV off-resonance energy points using the full data sample collected by the Belle detector with an integrated…