Related papers: Determination of color-octet matrix elements from …
We revisit the $J/\psi$ pair production issue at the Fermilab Tevatron Run II with the center-of-mass energy $\sqrt{s}=1.96 \mathrm{TeV}$. Both color-singlet and -octet production mechanisms are considered. Our result shows that the…
Exclusive semileptonic and nonleptonic $J/\psi$ decays are investigated in the framework of the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The form factors parameterizing the hadronic matrix…
At present the color-octet mechanism is still an important and debatable part in the non-relativistic QCD(NRQCD). We find in this work that the polarized double charmonium production at the LHC may pose a stringent test on the charmonium…
Color-octet contributions to the associate J/psi+gamma hadroproduction are studied in detail, and found to be negligible, compared to the ordinary color-singlet contribution. Within the color-singlet model the J/psi+gamma production in the…
Direct $J/\psi$ and $\psi'$ production rates at Tevatron are calculated in the $k_t$-factorization approach within the color-singlet model. In this approach, the production rates are enhanced by a factor of 20 compared to the naive…
We calculate the production and polarization of direct $J/\psi$ in the improved color evaporation model at $\mathcal{O}(\alpha_s^3)$ in the collinear factorization approach. We present the first calculation of polarization parameters…
The cross section of the process $e^+e^- \to K_S^0 K_S^0\pi^+\pi^-$ has been measured using a data sample of 56.7 pb$^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider. 596$\pm$27 and 210$\pm$18 signal events have…
Using data samples with an integrated luminosity of 22.42 fb$^{-1}$ collected by the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the $e^{+}e^{-}\rightarrow\etaJ/\psi$ process at center-of-mass…
An analysis of inelastic photoproduction of J/Psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80pb-1. Differential and double differential cross sections are measured…
The cross section of the process e+ e- --> omega pi0 --> pi0 pi0 gamma has been measured in the c.m. energy range 920-1380 MeV with the CMD-2 detector. Its energy dependence is well described by the interference of the rho(770) and…
The cross sections for inelastic photoproduction of J/psi and psi' mesons have been measured in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 38.0 pb-1. The events were required to have 0.1 < z < 0.9 and 50…
Using data samples with an integrated luminosity of $6.4$~fb$^{-1}$ collected by the BESIII detector operating at the BEPCII storage ring, the process of $e^+e^-\to\gamma\phi J/\psi$ is studied. The processes of $e^+e^-\to\phi\chi_{c1,c2}$,…
Prompt double-$J/\psi$ production at high-energy hadron colliders can be considered as a golden channel to probe double parton scatterings (DPS) --in particular to study gluon-gluon correlations inside the proton-- and, at the same time, to…
We consider the contributions of both color-singlet and octet $c\bar c$ bound states for studying the suppression of $J/\psi$ production in quark gluon plasma (QGP) and have found that the existence of the color-octet $c\bar c$ may cause…
Measurements by the Belle Collaboration of the cross section for inclusive J/psi production in e^+e^- annihilation have been a serious challenge to current heavy-quarkonium theory. Especially, the measured cross sections for exclusive…
The cross section of the process $e^+e^- \to K_S^0 K^{\pm}\pi^{\mp}\pi^+\pi^-$ has been measured for the first time using a data sample of 185.4 pb$^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider. With the…
Inelastic and diffractive production of J/psi mesons at HERA is reviewed. The data on inelastic photoproduction are described well within errors by the Colour Singlet Model in next-to-leading order. A search for colour octet processes…
The chromoelectric polarizability of $J/\psi$ is extracted from lattice QCD data on the nucleon-$J/\psi$ potential in the heavy quark limit. The value of $\alpha(1S) = (1.6 \pm 0.8) \,{\rm GeV}^{-3} $ is obtained. We also comment on the…
J/psi production in top quark rare decays is investigated under the framework of NRQCD factorization formalism. Various production channels are studied, and we find that the contributions from the color-singlet quark fragmentation and the…
Working in the nonrelativistic-QCD factorization framework at next-to-leading order in $\alpha_s$, we fit the relevant color octet (CO) long-distance matrix elements (LDMEs) of the $\psi(2S)$ meson, $\langle {\cal…