相关论文: Nucleon sea and the five-quark components
We investigate shadowing effects in deep-inelastic scattering from nuclei at small values $x<0.1$ of the Bjorken variable. Unifying aspects of generalized vector meson dominance and color transparency we first develop a model for…
The recent progress on our understanding of the flavor structure of unpolarized and polarized nucleon sea is reviewed. The large flavor asymmetry between the up and down sea quark distributions is now well established. This asymmetry…
The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02<x<0.3 and 1 GeV^2<Q^2<10 GeV^2, for the first time from semi-inclusive deep-inelastic scattering. The quantity…
We investigate the sea quark polarization in the nucleon by means of a combined next to leading order analysis to the recently enlarged set of inclusive and semi-inclusive polarized deep inelastic scattering data. Using the Lagrange…
We estimate the effects on the decay constants of charmonium and on heavy meson masses due to the charm quark in the sea. Our goal is to understand whether for these quantities $N_f=2+1$ lattice QCD simulations provide results that can be…
Neutrino induced deep inelastic charm production off strange sea partons in the nucleon is studied in the framework of the MSbar fixed flavor factorization scheme. The momentum (z) distributions of the produced D mesons as calculated in the…
We present a general analysis of the spin transfer for $\Lambda$ and $\bar{\Lambda}$ production in deep-inelastic scattering of polarized charged leptons on the nucleon, and find that the pattern of different behaviors of $\Lambda$ and…
A physical model for parton densities in hadrons, based on Gaussian momentum fluctuations of partons and hadronic baryon-meson fluctuations, is presented. The model has previously been shown to describe proton structure function data, and…
The isospin asymmetry of the sea quark distribution as well as the unexpectedly small quark spin fraction of the nucleon are two outstanding discoveries recently made in the physics of deep-inelastic structure functions. We evaluate here…
In this paper we present the derivation as well as the numerical results for all electromagnetic form factors of the nucleon within the chiral quark soliton model in the semiclassical quantization scheme. The model is based on a…
The detection of gravitational waves from GW170817 has provided a new opportunity to constrain the equation of state (EOS) of neutron stars. In this article, we investigate the possible existence of quarks inside the neutron star core in…
Moments of unpolarized, helicity, and transversity distributions, electromagnetic form factors, and generalized form factors of the nucleon are presented from a preliminary analysis of lattice results using pion masses down to 359 MeV. The…
We have made next to leading order QCD fit to the deep inelastic spin asymmetries on nucleons and we determined polarised quark and gluon densities. The functional form for such distributions was inspired by the Martin, Roberts and Stirling…
We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles…
Contributions to the quark flavor and spin observables from the intrinsic charm in the proton are discussed in the SU(4) quark meson fluctuation model. Our results suggest that the probability of finding the intrinsic charm in the proton is…
Nuclei are transparent for a heavy intrinsic charm (IC) component of the beam hadrons, what leads to an enhanced nuclear dependence of open charm production at large Feynman x_F. Indeed, such an effect was observed recently in the SELEX…
Quark matter with only $u$ and $d$ quarks ($ud$QM) might be the ground state of baryonic matter at large baryon number $A>A_{\rm min}$. With $A_{\rm min}\gtrsim 300$, this has no direct conflict with the stability of ordinary nuclei. An…
The possibilities to determine the flavor structure of the polarized sea (antiquark) distributions of the nucleon via vector boson $(\gamma^*, W^{\pm}, Z^0)$ production at high energy polarized hadron--hadron colliders, such as the…
We extend the QCD Parton Model analysis using a factorized nuclear structure model incorporating individual nucleons and pairs of correlated nucleons. Our analysis of high-energy data from lepton Deep-Inelastic Scattering, Drell-Yan and W/Z…
The light-quark flavor dependence of the proton sea has been of great interest for many years because of its close connection with non-perturbative effects. One hypothesis is that this dependence arises from the pion cloud of the proton. We…