Related papers: Proton Spin in Chiral Quark Models
Several spin and flavor dependent parameters characterizing the strangeness content of the nucleon have been calculated in the chiral constituent quark model with configuration mixing (\chiCQM_{config}) which is known to provide a…
The leading chiral contributions to the quark and gluon components of the proton spin are calculated using heavy-baryon chiral perturbation theory. Similar calculations are done for the moments of the generalized parton distributions…
The proton spin puzzle has inspired a vast programme of experiments and theoretical work challenging our understanding of QCD and its role in the structure of hadrons.The proton's internal spin structure is connected to chiral symmetry and,…
We calculate with chiral symmetry the parton contents of the proton based on a two-component wave function. The calculation results give significant sea-quark contents and, especially, the intrinsic gluon polarization produced at a more…
We investigate the structure of constituent quarks and study implications for quark distribution functions of hadrons. Constituent quarks are constructed by dressing bare quarks with Goldstone bosons using the chiral quark model. We…
The relatively small fraction of the spin of the proton carried by its quarks presents a major challenge to our understanding of the strong interaction. Traditional efforts to explore this problem have involved new and imaginative…
After a brief review of the experimental results obtained in deep inelastic lepton-nucleon scatterings and the Drell-Yan processes and their implications for the spin and flavor contents of the nucleon, we suggest that those features, that…
Employing the experimental electro-weak interactions between quarks and leptons, the spin of the proton may easily be understood in terms of the spins of the constituent quarks.
The fact that the spins of the quarks in the proton, as measured in deep inelastic lepton scattering, only add up to about 30$\%$ of the spin of the proton is still not understood after 30 years. We show that our newly developed model for…
We investigate the quark spin content of the SU(3) baryon octet, decuplet, antitriplet, and sextet in a pion mean-field approach or the chiral quark-soliton model, considering the $1/N_c$ rotational corrections and SU(3) symmetry breaking…
Recent developments and open issues in chiral dynamics with strange quarks are reviewed. Topics include: Order parameters of chiral symmetry breaking, the flavor dependence of these order parameters, speculations about the phase structure…
An unified scheme for describing both spin and orbital motion in symmetry-breaking chiral quark model is suggested. The analytic results of the spin and orbital angular momenta carried by different quark flavors in the nucleon are given.…
In the low-energy regime light and strange baryons should be considered as systems of constituent quarks with confining interaction and a chiral interaction that is mediated by Goldstone bosons as well as by vector and scalar mesons. The…
Asymmetries in the quark momentum distributions in the proton reveal fundamental aspects of strong interaction physics. Differences between u-bar and d-bar quarks in the proton sea provide insight into the dynamics of the pion cloud around…
Effect of the quark intrinsic motion on the proton spin structure functions is demonstrated. It is shown, that the covariant version of the quark-parton model taking into account the orbital motion gives the consistent picture of the proton…
Considerable progress has been made in our knowledge of the spin distribution within the proton. The recently measured limits on polarized gluons in the proton suggest polarized gluons contribute very modestly to the proton spin. We will…
Proton spin is investigated in chiral effective field theory through an examination of the singlet axial charge, $a_0$, and the two non-singlet axial charges, $a_3$ and $a_8$. Finite-range regularization is considered as it provides an…
The present empirical information on the strangeness form factors indicates that the corresponding $uuds\bar s$ component in the proton is such that the $uuds$ subsystem has the flavor spin symmetry $[4]_{FS}[22]_F[22]_S$ and mixed orbital…
The proton spin puzzle has challenged our understanding of QCD for the last 20 years. We survey new developments in theory and experiment. The proton spin puzzle seems to be telling us about the interplay of valence quarks with chiral…
The twenty years since the announcement of the proton spin crisis by the European Muon Collaboration has seen tremendous progress in our knowledge of the distribution of spin within the proton. The problem is reviewed, beginning with the…