Related papers: Instanton-induced charm contribution to polarized …
Measurement of $Z$ bosons produced in association with charm jets $(Zc)$ in proton-proton collisions in the forward region provides a direct probe of a potential non-perturbative (intrinsic) charm component in the proton wave function. We…
We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes.…
In this paper, we have investigated the importance of quark charm in nuclear structure functions in the color dipole model at small $x$. The charm structure function per nucleon $F_{2}^{cA}/A$ for light and heavy nuclei in a wide range of…
A recently proposed strategy to quantify the role of the charm quark mass in the $\Delta I=1/2$ rule is reviewed. Results for the low-energy couplings of the $\Delta S=1$ chiral effective Hamiltonian in a theory with a light charm quark…
Charm production in charged current deep inelastic scattering has been measured for the first time in $e^{\pm}p$ collisions, using data collected with the ZEUS detector at HERA, corresponding to an integrated luminosity of $358 pb^{-1}$.…
Several recent measurements of charmed hadron production in deep inelastic scattering at HERA are reviewed. Cross sections for the production of D mesons were measured and compared to NLO QCD predictions. The charm contribution to the…
We study the possibility of intrinsic (non-perturbative) charm in parton distribution functions (PDF) of the proton, within the context of the CT10 next-to-next-to-leading order (NNLO) global analysis. Three models for the intrinsic charm…
The coefficient functions for heavy-flavour production in deeply inelastic electron-hadron scattering have been calculated previously. Analytic expressions are impossible to publish due to their length. Therefore we have tabulated them as…
I discuss the instanton-induced contributions to the coefficient functions in front of parton densities. They correspond to the spherically symmetric particle production at the level of $10^{-2}-10^{-5}$ of the total cross section of deep…
Neutrino deep-inelastic scattering provides a means to study both the strange and charm content of the nucleon. The NuTeV experiment (Fermilab E-8Neutrino deep-inelastic scattering provides a means to study both the strange and charm…
We discuss few, apparently different, but actually tightly related problems: a)Strangeness in the nucleon; b) B --> eta' decays; c)Intrinsic charm in the proton spin problem. We argue that all these problems have a common origin and related…
We compute the decay rate for the process $\eta_c\to p\bar p$ using an effective helicity-flipping proton-antiproton-gluon vertex which incorporates nonperturbative chiral symmetry breaking effects induced by instantons. We fix the strength…
The possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon is investigated together with theoretical issues arising in its interpretation. Results from the global PDF analysis…
We calculate the azimuthal dependence of the heavy-quark-initiated ${\cal O}(\alpha_{s})$ contributions to the lepton-nucleon deep inelastic scattering (DIS). It is shown that, contrary to the photon-gluon fusion (GF) component, the…
We study $D$ - meson production at forward rapidities taking into account the non - linear effects in the QCD dynamics and the intrinsic charm component of the proton wave function. The total cross section, the rapidity distributions and…
According to general understanding, the proton as one of the main ingredients of the nucleus is composed of one down and two up quarks bound together by gluons, described by Quantum Chromodynamics (QCD). In this view, heavy quarks do not…
We investigate the contribution of the charm-anticharrm ($c{\bar c}$) asymmetry of the proton eigenstate obtained from QCD lattice gauge to the asymmetry of $D^+D^-$ and $D^0{\bar D}^0$ mesons produced in $pp$ collisions at large Feynman…
We have performed a QCD next-to-leading order (NLO) calculation for Deep Inelastic Scattering (DIS) retaining the full parton and hadron mass dependencies. We find that the gluon initiated contributions to DIS processes, such as charm…
The process of charm quark fragmentation is studied using $D^{*\pm}$ meson production in deep-inelastic scattering as measured by the H1 detector at HERA. Two different regions of phase space are investigated defined by the presence or…
The contribution of the anomalous quark-gluon interaction induced by instantons to the polarized and unpolarized gluon distributions in nucleon is estimated. It is shown that this interaction leads to negative gluon polarization in nucleon.