Related papers: Rescattering Effects in Quarkonium Production
We investigate the inclusive hadroproduction of a heavy quarkonium ($J/\psi$ or $\Upsilon$), in association with a light-flavored jet, as a testing ground for the semi-hard regime of QCD. Our theoretical setup is the hybrid high-energy and…
We extend to large transverse momentum pt an approach to quarkonium hadroproduction previously suggested for low pt. The dynamics involves a perturbative rescattering of the heavy quark pair off a comoving color field which originates from…
The NRQCD factorization approach for quarkonium production at hadron colliders is reviewed. The prediction of J/psi and psi(2S) transverse polarization at large transverse momentum is confronted with recent experimental data, and potential…
It has been suggested that the suppression of $J/\psi$ production in heavy nuclei is a signature of the formation of quark-gluon plasma. We here show that this phenomenon can be understood in terms of conventional physics, {\it i.e.} {\it…
We propose that the process of triple prompt $J/\psi$ hadroproduction is a very clean hard probe of multiple-parton scatterings at high-energy hadron colliders, especially the least known triple-parton scattering. A first complete study is…
Coherent multiple scatterings of c and cbar quark pairs in the environment of heavy ion collisions have been used in a previous work by Qiu et al. [Qiu:1998rz] to study J/psi suppression. That model suggests that heavy quark re-scatterings…
We calculate the cross sections for the direct hadroproduction of J/psi and Upsilon associated with a heavy-quark pair of the same flavour at leading order in alpha_S and v in NRQCD. These processes provide an interesting signature that…
In terms of multiple scattering picture, we calculate the double scattering effect in the transverse momentum distribution of $J/\psi$ photoproduction. Applying the generalized factorization theorem, we find that the contributions from…
We review the extension of the factorization formalism of perturbative QCD to {\it coherent} soft rescattering associated with hard scattering in high energy nuclear collisions. We emphasize the ability to quantify high order corrections…
There are many outstanding discrepancies comparing the predictions of perturbative QCD and measurements of the rate of production and decay of heavy quark systems. The problems include the $J/\psi \to \rho \pi$ puzzle, leading charmed…
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…
Quarkonium production is a sensitive probe of the dynamics of hard scattering, which can `measure' the environment of the heavy quark pair after it is created in a hard process. Quarkonium hadroproduction data indicates that the produced…
We examine angular distributions of leptons arising from the decay of J/psi in inclusive hadroproduction. Taking into account feed-down contributions from chi_{1,2}, a flat distribution emerges without fine tuning parameters. Changes in the…
Quarkonium production in proton-proton collision is interesting in profiling the partons inside the nucleon. Recently, the impact of double parton scatterings (DPSs) was suggested by experimental data of associated quarkonium production…
Exclusive quarkonium pair production in electron-positron collisions is studied in non-relativistic QCD. The obtained cross section for J/\psi + \eta_c production in the leading order is confronted against the recent measurements by the…
Rescattering effects of baryon and antibaryon in heavy quarkonium decays are investigated by studying their angular distributions. The rescattering amplitudes are phenomenologically evaluated by modeling the intermediate range interaction…
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…
In this paper we discuss the inclusive $J/\psi$ production in proton-proton collisions from fusion of three pomerons. We demonstrate that this mechanism gets dominant contribution from the region which can be theoretically described by…
On the basis of the generalized eikonal approximation we study the exclusive reactions $\bar p d \to J/\psi\, n$ and $\bar p d \to \psi^\prime\, n$ in vicinity of the thresholds for charmonium production on a free proton target. It is shown…
The three-gluon contribution to $J/\psi$ hadroproduction is calculated within perturbative QCD in the $k_T$ factorization framework. This mechanism involves double gluon density and enters at a non-leading twist, but it is enhanced at large…