相关论文: Sea quark polarization and semi-inclusive DIS data

Measurements of parity-violating asymmetries in DIS region using the SoLID spectrometer at Jefferson Lab (JLab) Hall A in the 12 GeV era are presented. A proposal with a polarized electron beam on unpolarized deuteron and proton targets has…

The first moments of the polarized valence parton distribution functions (PDFs) truncated to the wide Bjorken $x$ region $0.004<x<0.7$ are directly (without any fitting procedure) extracted in the next to leading order (NLO) QCD from both…

A comprehensive analysis of deep inelastic scattering of polarized charged leptons on polarized nucleons is presented; weak interaction contributions, both in neutral and charged current processes, are taken into account and the parity…

A wide range of nucleon and nuclear structure experiments in Jefferson Lab's Hall A require precise, continuous measurements of the polarization of the electron beam. In our Compton polarimeter, electrons are scattered off photons in a…

Recently the possible existence of negative gluon helicity, $\Delta g$, has been observed to be compatible with existing empirical constraints, including from jet production in polarized proton-proton collisions at RHIC, and lattice QCD…

The inclusive polarized structure functions of the proton and deuteron, g1p and g1d, were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory.…

Polarized semi-inclusive deep-inelastic scattering (SIDIS) is a key process in the quest for a resolution of the proton spin puzzle. We present the complete results for the polarized SIDIS process at next-to-next-to-leading order (NNLO) in…

Polarization measurements are the best instrument to understand how quark and antiquark combine into the different quarkonium states, but no model has so far succeeded in explaining the measured J/psi and Upsilon polarizations. On the other…

It is demonstrated that new JLAB proton polarization data, which are in a rather strong disagreement with the proton electric form factor data in the space-like region obtained by Rosenbluth technique, are consistent with all known form…

We present an improved determination of the strange sea distribution in the nucleon with constraints coming from the recent charm production data in neutrino-nucleon deep-inelastic scattering by the NOMAD and CHORUS experiments and from…

We present a quantitative assessment of the impact a future electron-ion collider will have on determinations of helicity quark and gluon densities and their contributions to the proton spin. Our results are obtained by performing a series…

Large double spin-asymmetries can be foreseen for Drell-Yan production in $p p$ scattering at JPARC energies. The sign of the asymmetries can be used to discriminate between different model calculations of sea quark distributions.

We review recent calculations using the quark meson coupling model which should be of particular interest at Jefferson Lab. In particular, we discuss the change in the proton electric and magnetic form factors when it is bound in a specific…

Several topics from the wide field of QCD studies in Deep-inelastic $ep$ Scattering at HERA are addressed. They include QCD analyses of the inclusive cross section with the determination of $\alpha_s$ and the proton gluon density from the…

Measurements of the polarization of the final proton in elastic e-p scattering drastically changed our knowledge about the electromagnetic form factors of the proton. Here we present our results of the calculation of the polarization of the…

The first CLAS12 experiments will provide high-precision data on inclusive electron scattering observables at a photon virtuality $Q^2$ ranging from 0.05 GeV$^2$ to 12 GeV$^2$ and center-of-mass energies $W$ up to 4 GeV. In view of this…

We have re-analyzed the world data on inclusive polarized DIS including the very precise CLAS proton and deuteron data, as well as the latest COMPASS data on the asymmetry $A_1^d$, and have studied the impact of these data on polarized…

An updated next-to-leading order (NLO) QCD analysis of all presently available longitudinally polarized deep-inelastic scattering (DIS) data is presented in the framework of the radiative parton model.

Generalized parton distributions describe the correlations between the longitudinal momentum and the transverse position of quarks and gluons in a nucleon. They can be constrained by measuring photon leptoproduction observables, arising…

Using a simple picture of the constituent quark as a composite system of point-like partons, we construct the polarized parton distributions by a convolution between constituent quark momentum distributions and constituent quark structure…