相关论文: Photoproduction of charm near threshold
The cross sections for charm and bottom quark production in the threshold region are discussed. We consider the effects of an all order resummation of initial state soft-plus-virtual gluon radiation on the total cross sections compared to…
Charm photoproduction rates off nuclei below the nucleon threshold are estimated using the phenomenologically known structure functions both for x>1 and x<1. The rates rapidly fall below the threshold from values of the order 10 pb for Pb…
Charm quarks are expected to be produced mainly by the photon-gluon fusion mechanism in photon-Nucleon interactions. However, a small part of the total charm cross section originates in similar processes to those appearing in charm…
Charm photoproduction rates off nuclei below the nucleon threshold are estimated using the phenomenologically known structure functions both for $x<1$ and $x>1$. The rates rapidly fall from values of the order 1 nb at the threshold to…
The charm quark photoproduction at large transverse momentum in the resolved photon interaction via partonic subprocess $\cg$ is studied. It is shown that at HERA energies the contribution of the charm quark excitation in the photon in the…
A review is given of the QCD corrections to charm quark production in deep inelastic electron-proton scattering. An outline of the computation of the virtual photon-parton subprocesses, from which one obtains the heavy quark coefficient…
Based on a perturbative theory of quantum chromodynamics and non-relativistic quark model, associated $J/\psi$ plus open charm photoproduction on charm quarks in a proton via partonic subprocess $\gamma c\to J/\psi c$ is discussed. It is…
We consider the photo-excitation of charm and bottom pentaquarks with the holographic assignments $[\frac 12\frac 12^-]_{S=0,1}$ and $[\frac 12\frac 32^-]_{S=1}$, in the photo-production of heavy vector mesons such as charmonia and…
We study the total cross section for photo production of open charm hadrons near threshold using a hadronic Lagrangian. Both two-body final states involving $\Lambda_c$ and a charmed meson as well as three-body final states involving…
Charm asymmetries in fixed-target hadroproduction experiments are sensitive to power corrections to the QCD factorization theorem for heavy quark production. A power correction called heavy-quark recombination has recently been proposed to…
Recent results on the hadroproduction of charm and beauty are discussed in the context of the current theoretical and experimental status. The areas covered include production of open charm and beauty particles and charm and beauty…
We discuss aspects of open and hidden charm production in hadron-nucleus collisions at RHIC and LHC energies. We first discuss the extraction of the total charm cross section in lower energy collisions and how it compares to next-to-leading…
The associative charm particles production in nucleon-nucleon collisions $N+N\to \Lambda_c(\Sigma_c)+\bar{D}+N$, is described in a general way and the spin and isospin structure of the corresponding matrix elements are derived. Using an…
The asymmetries between charm and anticharm mesons observed in fixed-target photoproduction experiments are an order of magnitude larger than the asymmetries predicted by conventional perturbative QCD. We show that these charm meson…
We present the first predictions for sub-threshold open charm and charmonium production in nuclear collisions. The production mechanism is driven by multi-step scatterings of nucleons and their resonance states, accumulating sufficient…
We present results on rapidity and transverse momentum distributions of inclusive charm quark production in hadronic and heavy-ion collisions at RHIC and LHC energies, including the next-to-leading order, $O(\alpha_s^3)$, radiative…
Heavy quarks, such as charm and beauty, possess masses significantly larger than the characteristic energy scale of Quantum Chromodynamics (QCD), and are thus predominantly produced in hard-scattering processes with large momentum transfer…
A study of the $\J$-meson photoproduction at large transverse momentum at HERA energies via the charm quark excitation in the photon is presented. Based on perturbative QCD, nonrelativistic quark model and photon structure function…
We report measurements of charmed hadron production from hadronic ($D^{0}\rightarrow K\pi$) and semileptonic ($\mu$ and $e$) decays in 200 GeV Au+Au collisions at RHIC. Analysis of the spectra indicates that charmed hadrons have a different…
I review the color dipole formulation of heavy quark production in the light of recent RHIC data. Since charm and bottom production directly probe the gluon density, these processes allow one to study shadowing and parton saturation at RHIC…