相关论文: Can the meson cloud explain the nucleon strangenes…
Effective quark magnetic moments are extracted from experimental measurements as a function of the strangeness magnetic moment of the nucleon. Assumptions made in even the most general quark model analyses are ruled out by this…
We perform a global analysis of all recent experimental data from elastic parity-violating electron scattering at low $Q^2$. The values of the electric and magnetic strange form factors of the nucleon are determined at $Q^2 = 0.1$ GeV/$c^2$…
We use light-front Holography to estimate the valence quark and the meson cloud contributions to the nucleon axial form factor. The free couplings of the holographic model are determined by the empirical data and by the information…
We discuss the role of strangeness in dense matter and especially in neutron stars. The early (in density) introduction of hyperons found in many calculations is probably delayed by the decrease in vector mean field acting on the neutron.…
The outcome of the SAMPLE Experiment suggests that the strange-quark contribution to the nucleon magnetic moment, G_M^s(0), may be greater than zero. This result is very difficult to reconcile with expectations based on the successful…
We have developed a physical model for the non-perturbative x-shape of parton density functions in the proton, based on Gaussian fluctuations in momenta, and quantum fluctuations of the proton into meson-baryon pairs. The model describes…
We use the meson cloud model of the nucleon to calculate distribution functions for $(\bar {d} - \bar{u})$ and $ \bar{d}/\bar{u}$ in the proton. Including the effect of the omega meson cloud, with a coupling constant $g_\omega^2/4\pi\approx…
The nucleon polarizabilities alpha(E) and beta(M) are studied in the context of the perturbative chiral quark model. We demonstrate that meson cloud effects are sufficient to explain the electric polarizability of nucleon. Contributions of…
We have applied the Meson Cloud Model to calculate inclusive momentum spectra of pions and kaons produced in high energy proton-proton and proton-nucleus collisions. For the first time these data are used to constrain the cloud cut-off…
The role of the sea quarks to ground state nucleon properties with electroweak probes is discussed. A relativistic Green's function approach to parity violating electron scattering and a distorted-wave impulse-approximation applied to…
A new measurement of the parity violating asymmetry in elastic electron scattering on hydrogen at backward angles and at a four momentum transfer of Q^2=0.22 (GeV/c)^2 is reported here. The measured asymmetry is A_LR=(-17.23 +- 0.82_stat…
We investigate the effects of mesonic clouds on neutron electric and nucleon strange form factors in the framework of the chiral quark soliton model. We present a mechanism to identify the mesonic clouds and their Yukawa tail in the…
We study the octet to decuplet baryon electromagnetic transitions using the covariant spectator quark model, and predict the transition magnetic dipole form factors for those involving the strange baryons. Utilizing SU(3) symmetry, the…
A careful reanalysis is done of the contribution to $K^{+}$ nucleus scattering from the interaction of the kaon with the virtual pion cloud. The usual approximations made in the evaluation of the related kaon selfenergy are shown to fail…
We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak…
The strange and antistrange quark distributions of the nucleon are less constrained by experimental data than the non-strange quark sea. The combination of light quark sea distributions, $\Delta(x)=\dbar(x)+\ubar(x)-s(x)-\sbar(x)$,…
This talk explores our lack of knowledge of the strange quark contribution to the nucleon spin, $\Delta s$. Data on $\Delta s$ from inclusive and semi-inclusive polarized deep-inelastic scattering will be reviewed, followed by a discussion…
Interactions of charmed and strange mesons with baryonic matter can be calculated in the nonrelativistic quark potential model. For KN scattering data exists, and the theoretical results for S-waves are in approximate agreement with…
We apply the perturbative chiral quark model at one loop to calculate the strange form factors of the nucleon. A detailed numerical analysis of the strange magnetic moments and radii of the nucleon, and also the momentum dependence of the…
We report on the contributions to the nucleon weak magnetic and electric form factors arising from isospin-breaking form factors. The relativized quark model used in the calculations includes isospin impurities in the large basis nucleon…