Related papers: Quark Flavor Separation in $\Lambda$-Baryon Fragme…
It is shown that the existence of left-right asymmetry in single-spin inclusive Lambda production, together with the characteristic features of the data, should be considered as another clear signature for the existence of orbiting valence…
Modified quark fragmentation functions in deeply inelastic $eA$ collisions and their QCD evolution equations are derived for the first time in the framework of multiple parton scattering. Induced radiation gives rise to additional terms in…
I give an overview of the present knowledge about nonperturbative functions parametrizing the fragmentation into one or two hadrons of (un)polarized light quarks in vacuum, including information on their transverse momentum dependence.
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…
We calculate the spin density matrix of the hadron $h$ created via quark fragmentation in the process $e^-e^+ \to q\bar q \to h + X$. In the case of $h=\Lambda$ the experimental data could possibly elucidate the problem of $s$-quark…
The flavor asymmetry of the nucleon sea is discussed in an unquenched quark model for baryons in which the effects of quark-antiquark pairs (u anti-u, d anti-d and s anti-s) are taken into account in an explicit form. The inclusion of q…
We investigate the sea quark polarization in the nucleon by means of a combined next to leading order analysis to the recently enlarged set of inclusive and semi-inclusive polarized deep inelastic scattering data. Using the Lagrange…
We consider Lambda-hyperon production in the target-fragmentation region of semi-inclusive deep-inelastic scattering within the framework of fracture functions. We present a first attempt to determine the flavour and energy dependences of…
We consider models for the spin transfers to $\Lambda$ and $\bar{\Lambda}$ hyperons produced in lepton-nucleon deep-inelastic scattering. We make predictions for longitudinal $\Lambda$ and $\bar{\Lambda}$ spin transfers for the COMPASS…
We investigate one-particle semi-inclusive processes in lepton-hadron scattering. In unpolarized scattering order $Q^{-1}$ corrections appear only when transverse momenta are detected. We consider the twist two and three matrix elements and…
We report on calculations of the charmonium and bottomonium spectrum in lattice QCD. We use ensembles of gauge fields with three flavors of sea quarks, simulated with the asqtad improved action for staggered fermions. For the heavy quarks…
A QCD analysis of the world data on polarized deep inelastic scattering is presented in next--to--leading order, including the heavy flavor Wilson coefficient in leading order in the fixed flavor number scheme. New parameterizations are…
In the paper, we calculate the fragmentation functions for a quark to fragment into a spin-singlet quarkonium, where the flavor of the initial quark is different from that of the constituent quark in the quarkonium. The ultraviolet…
Recent deep inelastic scattering and Drell-Yan experiments have revealed a surprisingly large asymmetry between the up and down sea quark distributions in the nucleon. The current status of the flavor asymmetry of the nucleon sea is…
Polarization of strange quarks is preserved to a high degree when they hadronize into Lambda baryons, as observed in Z decays at LEP. This opens up the possibility for ATLAS and CMS to use strange-quark polarization measurements as a…
We report recent experimental and theoretical progress concerning the heavy-quark electro-production in the context of the ABM11 parton distribution function (PDF) fit. In the updated ABM11 analysis, including the recent combined HERA charm…
Polarized flavor asymmetry Delta u-bar/Delta d-bar is investigated in a meson-cloud model. A polarized nucleon splits into a rho meson and a baryon, then the polarized rho meson interacts with the virtual photon. Because of the difference…
Deep-inelastic production of heavy quarks at HERA, especially charm, is an excellent signal to measure the gluon distribution in the proton at small $x$ values. By measuring various differential distributions of the heavy quarks this…
While jet quenching in relativistic heavy-ion collisions has been extensively studied over decades, the polarization of quenched hadrons has rarely been discussed. It has recently been proposed that the correlations of dihadron polarization…
We provide a first calculation of the complete next-to-leading order QCD corrections for heavy flavor contributions to the inclusive structure function $g_1$ in longitudinally polarized deep-inelastic scattering. The results are derived…