相关论文: Flavor Asymmetry in Hyperons and Drell-Yan Process…
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 use the meson cloud model and the Sullivan mechanism to estimate the sea flavor asymmetry in the \Sigma^+ baryon and calculate the distribution functions of both sea and valence quarks. We find large deviations from SU(3).
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…
We discuss the present status of the \bar u-\bar d asymmetry in the nucleon and analize the quantities which are best suited to verify the asymmetry. We find that the Drell-Yan asymmetry is the quantity insensitive to the valence quark…
We apply the Meson Cloud Model to the calculation of nonsinglet parton distributions in the nucleon sea, including the octet and the decuplet cloud baryon contributions. We give special attention to the differences between nonstrange and…
The flavor asymmetry of the nucleon sea, i.e., the excess of $d\bar{d}$ quark-antiquark pairs over $u\bar{u}$ ones in the proton can be explained by several different models; therefore, it is a challenge to discriminate these models from…
The sea quark content of the $\Sigma^+$ baryon is investigated using light-cone baryon-meson fluctuation model suggested by Brodsky and Ma. It is found that the $\Sigma^+$ sea is flavour asymmetric ($\dbar > \ubar > \sbar$) and…
We investigate how Drell-Yan processes can be used to measure the magnitude of flavor symmetry violation in the proton sea. We examine the utility of the following beams: protons, charged pions, and charged kaons. In each case we present an…
The quark flavor and spin distributions in octet baryons are calculated both in the SU(6) quark spectator diquark model and in a perturbative QCD (pQCD) based model. It is shown that the $\Lambda$ has the most significant difference in…
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…
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 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…
The light flavor antiquark distributions of the nucleon sea are calculated in the effective chiral quark model and compared with experimental results. The contributions of the flavor-symmetric sea-quark distributions and the nuclear EMC…
The quark flavor distribution functions of the octet baryons ($N$, $\Sigma$, $\Xi$ and $\Lambda$) have been calculated in the chiral constituent quark model ($\chi$CQM). In particular, the valence and sea quark flavor distribution functions…
I review progress in calculating strange quark and antiquark distributions of the nucleon using the meson cloud model. This progress parallels that of the meson cloud model, which is now a useful theoretical basis for understanding symmetry…
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…
Parton distributions derived from a chiral quark model that generates an excess of down quarks and antiquarks in the proton's sea satisfactorily describe the measured yields of muon pairs produced in proton-nucleus collisions. Comparison of…
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 show that the chiral $SU(n)\otimes SU(n)$ flavor symmetry on the null-plane severely restricts the sea quarks in the baryon octet. It predicts large asymmetry for the light sea quarks $(u,d,s)$, and universality and abundance for the…
We show that the chiral $SU(n)\otimes SU(n)$ flavor symmetry on the null-plane severely restricts the sea quarks in the baryon octet. It predicts large asymmetry for the light sea quarks $(u,d,s)$, and universality and abundance for the…