Related papers: Strange quark helicity in the proton from chiral e…
The helicity-dependent strange quark distribution in the proton, $\Delta s$, is calculated in a nonlocal chiral SU(3) effective field theory. The hadronic proton to meson plus octet or decuplet baryon splitting functions are derived at the…
The strange quark helicity distribution Delta s(x)is derived at LO from the semi-inclusive and inclusive spin asymmetries measured by the COMPASS experiment at CERN. The significance of the results is found to depend critically on the ratio…
By analyzing experimental data on semi-inclusive deep inelastic scattering off longitudinally polarized targets, we extract the transverse momentum dependence of the quark helicity distribution, i.e., the difference between the…
We present a systematic study of the proton spin structure in terms of measurable parton distributions. For a transversely-polarizedproton, we derive a polarization sum rule from the leading generalized parton distributions appearing in…
We discuss the spin structure of the proton in a light-cone treatment of the chiral quark model. Based on the fact that the quark helicity ($\Delta q$) measured in polarized deep inelastic scattering experiments is actually the quark spin…
We present a new formulation of pseudoscalar meson loop corrections to nucleon parton distributions within a nonlocal covariant chiral effective field theory, including contributions from SU(3) octet and decuplet baryons. The nonlocal…
The spin fractions and deep inelastic structure functions of the proton are analyzed using chiral field theory involving Goldstone bosons. A detailed comparison with recent chiral models sheds light on their successful description of the…
We propose new method which allows determination of the strange-sea quark spin distribution in the nucleon through measurement of various inclusive and semi-inclusive polarized deep inelastic electron- or muon-proton reactions. It is shown,…
In the past year, polarized deep inelastic scattering experiments at CERN and SLAC have obtained structure function measurements off proton, neutron and deuteron targets at a level of precision never before achieved. The measurements can be…
We investigate the transverse quark spin densities of the nucleon with the lowest moment within the framework of the SU(3) chiral quark-soliton model, emphasizing the strange quark spin density. Based on previous results of the vector and…
We propose a unified new approach to describe polarized and unpolarized quark distributions in the proton based on the gauge-gravity correspondence, light-front holography, and the generalized Veneziano model. We find that the…
We calculate the chiral odd quark distributions and the corresponding structure functions $h_T(x,Q^2)$ and $h_L(x,Q^2)$ within the Nambu-Jona-Lasinio chiral soliton model for the nucleon. The $Q^2$ evolution of the twist-2 contributions is…
We present an improved determination of the strange quark and anti-quark parton distribution functions of the proton by means of a global QCD analysis that takes into account a comprehensive set of strangeness-sensitive measurements:…
We discuss techniques and results for the extraction of the nucleon's spin-dependent parton distributions and their uncertainties from data for polarized deep-inelastic lepton-nucleon and proton-proton scattering by means of a global QCD…
We compute the helicity skewed quark distributions $\widetilde{H}$ and $\widetilde{E}$ in the chiral quark-soliton model of the nucleon. This model emphasizes correctly the role of spontaneously broken chiral symmetry in structure of…
By assuming that there is no significant intrinsic polarization of the gluon, we have computed the polarized quark contributions to the proton's spin under SU(3) flavor symmetry breaking for the polarized sea and have performed a global…
We present, for the first time, an \textit{ab initio} calculation of the individual up, down and strange quark helicity parton distribution functions for the proton. The calculation is performed within the twisted mass clover-improved…
We consider the role of chirally odd wave functions in hard exclusive reactions. Such wave functions have the quarks oriented in the opposite helicity configuration from those assumed in the short-distance limit and are generally associated…
In this paper a discussion is made of the article by the HERMES Collaboration, Phys.Lett. B666,446, where several important results concerning strange quark properties in the nucleon were presented. By analysing the sum of K+-…
We present results on the quark unpolarized, helicity and transversity parton distributions functions of the nucleon. We use the quasi-parton distribution approach within the lattice QCD framework and perform the computation using an…