Related papers: Recent Developments in Heavy Quark and Quarkonium …
It has recently been noticed that heavy quark ($Q$) and gluon ($g$) fragmentation to heavy quarkonium states ($Q\bar{Q}$) can be calculated in perturbative QCD. This technique allows for the inclusion of a subset of higher order corrections…
We present a perturbative QCD factorization formalism for the production of heavy quarkonia of large transverse momentum $p_T$ at collider energies, which includes both the leading power (LP) and next-to-leading power (NLP) contributions to…
We investigate the charm hadron production in relativistic heavy-ion collisions with the quark combination model. The $p_{T}$ dependencies of the charm baryon to meson ratios such as…
We discuss some new aspects of charm production trigerred by recent observations of the LHCb collaboration. The LHCb collaboration measured small asymmetries in production of $D^+ D^-$ mesons as well as $D_s^+ D_s^-$ mesons. Is this related…
A QCD factorization formalism was recently proposed for evaluating heavy quarkonium production at large $p_T$ at collider energies. With systematically calculated short-distance partonic hard parts and evolution kernels of fragmentation…
Recently, a new perturbative QCD factorization formalism for heavy quarkonium production at a large transverse momentum was proposed. Phenomenological application of this new approach relies on our knowledge of a large number of universal…
We study contributions from color-octet quarkonium formation mechanisms to $J/\psi$ hadroproduction at low $p_\perp$. We include transitions of color-octet $c\bar{c}$ states into ``direct'' $J/\psi$ and into $\chi_{1,2}$ which decay…
Considering the possibility to build an $e^+ e^-$ collider at the energies around the $Z^0$-boson resonance with a planned luminosity so high as ${\cal L}\propto 10^{34}\sim 10^{36}cm^{-2}s^{-1}$ (super $Z$-factory), we make a detailed…
We calculate the next-to-leading-order (NLO) QCD corrections to $e^+e^-\to J/\psi g g$ via color singlet $J/\psi(^3{-0.8mm}S_1)$ at the B factories. The result shows that the cross section is enhanced to $0.373\pb$ by a K factor (NLO/LO) of…
We discuss the various mechanisms potentially at work in hadroproduction of heavy quarkonia in the light of computations of higher-order QCD corrections both in the Colour-Singlet (CS) and Colour-Octet (CO) channels and the inclusion of the…
We calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to $\gamma+\gamma\to \eta_c+c+\bar{c}$, $\gamma+\gamma\to \eta_b+b+\bar{b}$ and $\gamma+\gamma\to B_c+b+\bar{c}$ processes in the framework of…
I review a few selected topics concerning heavy-quark fragmentation, taking particular care about bottom- and charm-quark production in $e^+e^-$ annihilation and the inclusion of non-perturbative corrections. In particular, I discuss recent…
Quarkonium production is an excellent probe to investigate the properties of the hot and dense medium, which can be created in heavy-ion collisions. The production and hadronisation of heavy quarks are well separated in the space-time…
We present a complete calculation of the higher-order perturbative QCD corrections to inelastic photoproduction of $J/\psi$ particles. A comprehensive analysis of total cross sections and differential distributions for the energy range of…
We present a calculation of the NLO QCD corrections to heavy flavor photoproduction with longitudinally polarized beams. We apply our results to study the spin asymmetry for total charm quark production which will be used for a first direct…
We describe a new approach to heavy-quark fragmentation which is based on a resummed perturbative calculation and parametrization of power corrections, concentrating on the z -> 1 limit, where the heavy meson carries a large fraction of the…
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…
Recent accurate data on F_2(x,Q) and on F_2^c(x,Q) from HERA at small-x require a more precise treatment of charm production in the global QCD analysis of parton distributions. We improve on existing global analyses by implementing the…
The study of $J/\psi$ photoproduction at low energies has consequences for the understanding of multiple aspects of nonperturbative QCD, ranging from mechanical properties of the proton, to the binding inside nuclei, and the existence of…
A study of hadron pair production mechanism is motivated by the recent observed decays $\bar B^0\to D^{(*)+}K^-K^0$. One novel phenomenon is threshold enhancement of the kaon pair production. We show that these decays in the heavy quark…