Related papers: Digluon contribution to $J/\psi$ production
We provide an update on our semi-classical transport approach for quarkonium production in high-energy heavy-ion collisions, focusing on $J/\psi$ and $\psi(2S)$ mesons in 5.02 TeV Pb-Pb collisions at the Large Hadron Collider (LHC) at both…
Thirty years ago, the suppression of charmonium production in heavy-ion collisions was first proposed as an unambiguous signature for the formation of a Quark-Gluon Plasma. Since then, experiments at fixed-target accelerators (SPS) and…
We discuss charm production at LHC. The production of single $c \bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. The hadronization is included with the…
Production of Higgs bosons at the LHC is affected by the contribution of light quarks, that mediate the gg \to Hg transition. Although their impact is suppressed by small Yukawa couplings, it is enhanced by large logarithms of the ratio of…
The study of azimuthal correlations in particle production at forward rapidities in proton-nucleus collisions provides direct information about high gluon density effects, like gluon saturation, in the nuclear wavefunction. In the…
We use perturbative QCD, beyond the leading $\ln Q^2$ approximation, to show how measurements of diffractive $J/\psi$ production at HERA can provide a sensitive probe of the gluon density of the proton at small values of Bjorken $x$. We…
The production of charmonium in heavy-ion collisions is investigated based on Boltzmann-type transport model for charmonium evolution and langevin equation for charm quark evolution. Charmonium suppression and regeneration in both…
I review possible resolution of the $J/\psi (\psi^{\prime}) \to \rho-\pi$ puzzle based on two inputs: the relative phase between the one- photon and the gluonic decay amplitudes, and a possible hadronic excess in the inclusive…
We study the process $\bar p p \rightarrow J/\psi + \gamma +X$ at the Tevatron energy ($\sqrt{s} = 1.8$~TeV). The perturbative QCD contributions to this process from the gluon-fusion and the fragmentation mechanisms are computed. For the…
We compute the contribution of third generation quarks ($t,\ b$) to the two-loop amplitude for on-shell $W$ boson pair production in gluon fusion $gg \to WW$. We present plots for the amplitude across partonic phase space as well as…
Quarkonium production at a given large p_T is dominated by parton fragmentation: a parton which is produced with transverse momentum p_T/z fragments into a quarkonium state which carries a fraction z of the parton momentum. Since parton…
Double parton fragmentation is a process in which a pair of partons produced in the short-distance process hadronize into the final state hadron. This process is important for quarkonium production when the transverse momentum is much…
The very large K-factor for Higgs-boson production at hadron colliders is shown to result from enhanced perturbative corrections of the form (C_A\pi\alpha_s)^n, which arise in the analytic continuation of the gluon form factor to time-like…
The production of charmonium associated with Higgs boson via gluon fusion has been investigated in Ref.[Phys.Rev.D66,114002(2002)], in which they considered the contribution of final Higgs boson radiation off the charm quark at tree level…
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…
We calculate the cross sections of associated $J/\psi + \psi^\prime$ and $J/\psi + J/\psi$ production in $pp$ collisions at $\sqrt s = 13$ TeV in the forward kinematic region. The High Energy Factorization ($k_T$-factorization) framework…
Perturbative analysis of parton kinetics for high energy nuclear collisions shows, that thermal equilibration of gluons happens very fast, while quark production is much slower. A simple 'minimal model' is proposed which includes only…
The dilepton production rate from the quark-gluon plasma is calculated from the imaginary part of the photon self energy using a quark propagator that contains the gluon condensate. The low mass dilepton rate obtained in this way exhibits…
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…
In this paper we discuss the systematics of quarkonium production at the LHC. In particular, we focus on the necessity to sum logs of the form log(Q/p_perp) and log(p_perp/m_Q). We show that the former contributions are power suppressed,…