On the flavour structure of the constituent quark

Szczurek, Antoni; Buchmann, A. J.; Faessler, Amand

doi:10.1088/0954-3899/22/12/004

Cited by 95 publications

(150 citation statements)

References 42 publications

Supporting

Mentioning

141

Contrasting

Order By: Relevance

“…Usually, it is assumed that Λ K = Λ π = 1500 MeV [29,31]. However, it is implied by the SU(3) f symmetry breaking that P K should be smaller, and, accordingly, one should adopt a smaller Λ K .…”

Section: Isospin Symmetry Breaking In the Chiral Quark Modelmentioning

confidence: 99%

Isospin symmetry breaking in the chiral quark model

Song

Zhang

2010

Phys. Rev. D

View full text Add to dashboard Cite

We discuss the isospin symmetry breaking (ISB) of the valence-and sea-quark distributions between the proton and the neutron in the framework of the chiral quark model. We assume that isospin symmetry breaking is the result of mass differences between isospin multiplets and then analyze the effects of isospin symmetry breaking on the Gottfried sum rule and the NuTeV anomaly.We show that, although both flavor asymmetry in the nucleon sea and the ISB between the proton and the neutron can lead to the violation of the Gottfried sum rule, the main contribution is from the flavor asymmetry in the framework of the chiral quark model. We also find that the correction to the NuTeV anomaly is in an opposite direction, so the NuTeV anomaly cannot be removed by isospin symmetry breaking in the chiral quark model. It is remarkable that our results of ISB for both valence-and sea-quark distributions are consistent with the Martin-Roberts-Stirling-Thorne parametrization of quark distributions.

show abstract

Section: Isospin Symmetry Breaking In the Chiral Quark Modelmentioning

confidence: 99%

Isospin symmetry breaking in the chiral quark model

Song

Zhang

2010

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…The excess ofd overū is then simply due to the additional valence u quark in the proton. Figure 15 includes the result of such a calculation, based on a calculation ofd(x) −ū(x) at Q 0 = 0.5 GeV/c by Szczurek et al [58], and evolved to Q 2 = 54 GeV 2 /c 2 . It clearly predicts too soft an asymmetry.…”

Section: Origins Of the Nucleon Seamentioning

confidence: 99%

Improved measurement of thed¯/ūasymmetry in the nucleon sea

et al. 2001

View full text Add to dashboard Cite

Measurements of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on liquid hydrogen and deuterium targets are reported. Approximately 360,000 Drell-Yan muon pairs remained after all cuts on the data. ¿From these data, the ratio of anti-down (d) to anti-up (ū) quark distributions in the proton sea is determined over a wide range in Bjorken-x. These results confirm previous measurements by E866 and extend them to lower x. From these data, (d −ū) and (d −ū)dx are evaluated for 0.015 < x < 0.35. These results are compared with parameterizations of various parton distribution functions, models and experimental results from NA51, NMC and HERMES. 13.85.Qk; 14.20.Dh; 24.85.+p; 14.65.Bt

show abstract

“…Another class of models which produces a flavor asymmetry in the nucleon via the inclusion of virtual mesons are the chiral quark models [38,39]. The chiral quark model is similar to the meson model, except the virtual meson couples directly to a quark, not the nucleon as a whole.…”

Section: Nonperturbative Originsmentioning

confidence: 99%

“…Figure 6.8 shows the chiral model prediction ford(x) −ū(x). This prediction was calculated following the formulation in reference [39]. The quantitȳ d(x) −ū(x) was calculated at Q = 0.5 GeV and then evolved to Q = 6.38 GeV.…”

Section: Nonperturbative Originsmentioning

confidence: 99%