Related papers: Heavy Quarkonium Production: Extending CSM and COM
We study and constrain the parameter space of the vector color-octet model from observed data at Tevatron by studying top quark pair production and associated observables afbt and spin-correlation. In particular we study invariant mass and…
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…
A new mechanism for heavy quarkonium production in high-energy collisions called the "s-channel cut" was proposed in 2005 by Lansberg, Cudell, and Kalinovsky. We identify this mechanism physically as the production of a heavy quark and…
Recent measurements of J/psi production in e^+ e^- colliders pose a challenge to the NRQCD factorization theorem for quarkonium production. Discrepancies between leading order calculations of color-octet contributions and the momentum…
It has been proposed that the large cross sections for prompt $\psi$, $\psi'$, and $\chi_c$ production at the Fermilab Tevatron $p\bar p$ collider can be explained by a dominant color-octet term in the fragmentation function for a gluon to…
Photoproduction of $J/\psi$ is considered including the color-octet contributions from the various partial wave states, $^{2S+1}L_J$ = $^1S_0$, $^3S_1$ and $^3P_J$. The production cross section depends on three new nonperturbative…
We compute \frac{d\sigma}{dp_T} of the J/\psi production in pp collisions at RHIC at \sqrt s = 500 and 200 GeV by using both the color octet and singlet models in the framework of non-relativistic QCD. The J/\psi we compute here includes…
The Color-Octet Model has been used successfully to analyze many problems in heavy quarkonium production. We examine some of the conceptual and practical problems of the soft gluon emission process in the Color-Octet Model. We use a…
The transverse momentum ($p_t$) distributions of production and polarization for $J/\psi$ measured by CDF Collaboration are still challenging our understanding of the heavy quarkonium production mechanism even with recent significant…
I describe the NRQCD factorization approach to the inclusive production of heavy quarkonium, contrasting it with the color-singlet and color evaporation models. These approaches differ dramatically in their assumptions about the roles…
We argue that the s-channel cut contribution to J/psi hadroproduction can be significantly larger than the usual cut contribution of the color-singlet mechanism, which is known to underestimate the experimental measurements. A scenario…
We investigate the pattern of asymmetries in the colour-octet model for inclusive production of charmonium with polarised initial state hadrons and photons. We find that singly polarised asymmetries vanish. The double polarised asymmetry…
Polarized heavy quarkonium productions in $Z^0$ decays are considered. We find that polarizations of the produced quarkonia are independent of that of the parent Z^0 provided that one considers the energy distribution or the total…
We anticipate new features of quarkonium production in heavy ion collisions at RHIC and LHC energies which differ from a straightforward extrapolation of results at CERN SPS energy. General arguments indicate that one may expect quarkonium…
In this contribution we briefly discuss an ongoing phenomenological programme on quarkonium production in unpolarized and polarized proton-proton collisions in a fixed target setup at LHCb, the LHCSpin project. Within a TMD approach, we aim…
We propose the measurement of $\chi_{cJ}$ polarizations at high energy hadron colliders to study heavy quarkonium production mechanism. We find that the color-singlet model in the $k_t$ factorization approach predicts very different…
We study the production of heavy quarkonium states in high energy proton-nucleus collisions. Following earlier work of Blaizot, Fujii, Gelis, and Venugopalan, we systematically include both small $x$ evolution and multiple scattering…
I compute the leading color-octet contributions to the process $\gamma + p \to J/\psi + \gamma (+ X)$ within the non-relativistic QCD (NRQCD) factorization formalism. In the color-singlet model, $J/\psi + \gamma$ can only be produced when…
The relativistic corrections to the productions of double J/psi, double Upsilon, and J/psi+Upsilon at the Tevatron and the LHC were investigated within the frame of nonrelativistic QCD. The ratios of short distance coefficients between…
Non-Relativistic QCD (NRQCD) has provided a consistent framework for the physics of quarkonia. The colour-octet Fock components predicted by NRQCD have important implications for the phenomenology of quarkonium production in experiments. We…