相关论文: Polarized light flavor sea-quark asymmetry in pola…
Simple formulas on $\Delta\bar d(x)-\Delta\bar u(x)$ are proposed for extracting their values from polarized deep-inelastic semi-inclusive data. The present SMC and HERMES data suggest that $\Delta\bar d(x)-\Delta\bar u(x)$ is slightly…
The flavor asymmetry of the polarized light sea, $\Delta \bar u - \Delta \bar d$, discriminates between different model calculations of helicity densities. We show that the chiral chromodielectric model, differently from models based on a…
We discuss the flavor asymmetry of polarized light antiquarks in the nucleon, $\Delta\bar{u}-\Delta\bar{d}$. We present a determination of this quantity based on two global QCD analyses of experimental data, DSSV08 and NNPDFpol1.1, in which…
The recent global analysis of helicity parton distributions, which takes into account available data from inclusive and semi-inclusive polarized deep inelastic scattering, as well as from polarized proton-proton scattering at RHIC, appears…
We investigate the flavour and quark-antiquark structure of the polarized nucleon by calculating the parton distribution functions of the nucleon sea using the meson cloud model. We find that the SU(2) flavor symmetry in the light antiquark…
Spin asymmetries of semi-inclusive cross sections for the production of positively and negatively charged hadrons have been measured in deep-inelastic scattering of polarized positrons on polarized hydrogen and 3He targets, in the kinematic…
We perform a combined next to leading order analysis to both inclusive and semi-inclusive polarized deep inelastic scattering data, assessing the impact of new data in the extraction of the sea quark and gluon spin dependent densities. In…
The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02<x<0.3 and 1 GeV^2<Q^2<10 GeV^2, for the first time from semi-inclusive deep-inelastic scattering. The quantity…
We perform a new extraction for unpolarized and polarized parton distribution functions considering a flavor decompositions for sea quarks and applying very recent deep inelastic scattering (DIS) and semi inclusive deep inelastic scattering…
We show that the model which naturally explains the $\bar u \ne \bar d$ asymmetry in the nucleon and is in quantitative agreement with the Gottfried sum rule data, also predicts that in the proton $\Delta \bar u > 0 > \Delta \bar s > \Delta…
Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions…
In connection with the semi-inclusive polarized DIS, it is proposed to consider the first Melin moments $\Delta q$ of the polarized quark and antiquark densities, instead of the respective variables $\delta q(x)$, local in Bjorken x…
We present the results of a QCD fit to global data on deep-inelastic polarised lepton-hadron scattering. We find that it is possible to fit the data with strongly broken SU(2) flavour for the polarised sea densities. This can easily be…
We describe a general approach to quark flavor tagging in polarized hadronic processes, with particular emphasis on semi-inclusive deep inelastic scattering. A formalism is introduced that allows one to relate chosen quark flavor…
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 polarized strange quark puzzle concerns the fact that the polarized strange quark density extracted from polarized inclusive deep inelastic scattering data is significantly negative, whereas it is zero or slightly positive when…
We show that measurements of semi-inclusive $\pi^\pm$ asymmetries on $p$ and $n$ with polarized and unpolarized target and beams allow, without any knowledge of the polarized parton densities 1) to test independent fragmentation and SU(2)…
We investigate the potential impact of forthcoming Jefferson Lab semi-inclusive polarized deep inelastic scattering proton measurements in the determination of the sea quark polarization in the nucleon by means of a next to leading order…
Flavor asymmetry is investigated in polarized light-antiquark distributions by a meson-cloud model. In particular, rho meson contributions to Delta u-bar - Delta d-bar are calculated. We point out that the g_2 part of rho contributes to the…
The fact that analyses of semi-inclusive deep inelastic scattering suggest that the polarized strange quark density $\Delta s(x) + \Delta \bar{s}(x)$ is positive in the measured region of Bjorken x, whereas all analyses of inclusive deep…