相关论文: Light flavor asymmetry of nucleon sea
Evidence for a flavor asymmetry between the $\bar u$ and $\bar d$ quark distributions in the proton has been found in deep-inelastic scattering and Drell-Yan experiments. The pronounced dependence of this flavor asymmetry on $x$ (fraction…
The asymmetries of both light-flavor antiquark $\bar{d}(x)-\bar{u}(x)$ and strange-antistrange $s(x)-\bar{s}(x)$ distributions of the nucleon sea are considered with more details in the effective chiral quark model. We find that the…
We compute the light antiquark flavor asymmetry in the proton using the Chiral Quark Model ($\chi_{\rm QM}$). The distribution functions for the light antiquarks $\bar{d}(x)$ and $\bar{u}(x)$ have been extracted with the help of…
We summarize recent attempts to calculate the flavor asymmetry of the nucleon's sea quark distributions in the large-$N_c$ limit, where the nucleon can be described as a soliton of an effective chiral theory. We discuss the leading-twist…
A precise measurement of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on liquid hydrogen and deuterium targets is reported. Over 370,000 Drell-Yan muon pairs were recorded. From these data, the ratio of anti-down…
Recent deep inelastic scattering and Drell-Yan experiments have revealed a surprisingly large asymmetry between the up and down sea quark distributions in the nucleon. In this article, we review the status of the flavor asymmetry of the…
Surprisingly large flavor asymmetry of the light-quark sea in the proton was reported in deep-inelastic scattering and Drell-Yan experiments. The Bjorken-$x$ dependence of the $\bar{d}/\bar{u}$ ratio extracted from the Fermilab E866…
Recent deep inelastic scattering and Drell-Yan experiments have revealed a surprisingly large asymmetry between the up and down sea quark distributions in the nucleon. The current status of the flavor asymmetry of the nucleon sea is…
The Fermilab E906/SeaQuest collaboration performed measurements of the Drell-Yan process using 120 GeV proton beams bombarding liquid hydrogen and liquid deuterium targets. A combined analysis of all collected data was performed to obtain…
A surprisingly large asymmetry between the up and down sea quark distributions in the nucleon has been observed in recent deep inelastic scattering and Drell-Yan experiments. This result strongly suggests that the mesonic degrees of freedom…
We discuss the flavor asymmetry of polarized light antiquarks in the nucleon, $\Delta\bar{u}-\Delta\bar{d}$. We present a determination of this quantity based on two global QCD analyses of experimental data, DSSV08 and NNPDFpol1.1, in which…
A precise measurement of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on hydrogen and deuterium targets is reported. Over 140,000 Drell-Yan muon pairs with dimuon mass M_{mu+ mu-} >= 4.5 GeV/c^2 were recorded. From…
We study the possible flavour asymmetry, $\bar{u} \neq \bar{d}$, of the light quark sea distributions of the proton. We discuss the information that is at present available from data on deep-inelastic lepton-nucleon scattering and from…
Theoretical predictions are given for the light-flavor sea-quark distributions including the strange quark ones on the basis of the flavor SU(3) version of the chiral quark soliton model. Careful account is taken here of the SU(3) symmetry…
Flavor asymmetries for the valence and sea quarks of the $\Sigma^{\pm}$ can be obtained from Drell-Yan experiments using charged hyperon beams on proton and deuteron targets. A large, measurable difference in sea quark asymmetries is…
We propose a flavor asymmetry in the light quark sea of $\Sigma^{\pm}$, which can be measured in Drell-Yan experiments using charged hyperon beams on proton and deuteron targets. Such a measurement would help to reinforce the presence of…
Using recently derived results for one-loop hadronic splitting functions from a nonlocal implementation of chiral effective theory, we study the contributions from pseudoscalar meson loops to flavor asymmetries in the proton. Constraining…
It is shown that accounting for the relativistic structure of the deuteron allows to explain the ratio of the Drell-Yan pair production cross-section at the low Bjorken $x$ off the deuteron and the proton. Thus, the sea quark distributions…
After taking account of the scale dependence by means of the standard DGLAP evolution equation, the theoretical predictions of the chiral quark soliton model for the unpolarized and longitudinally polarized structure functions of the…
SU(2)-flavor-symmetry breaking in antiquark distributions of the nucleon was suggested by the New Muon Collaboration (NMC) in deep inelastic muon scattering. As an independent test, Drell-Yan data for the tungsten target have been used for…