Flavor and Spin Structure of $\Lambda$-Baryon at Large x

Abstract

It is shown that a perturbative QCD (pQCD) based analysis and the SU(6) quark-diquark model give significant different predictions concerning the flavor and spin structure for the quark distributions of the $\Lambda$-baryon near $x=1$. Detailed predictions for the ratios $u(x)/s(x)$ of unpolarized quark distributions, $\Delta s(x)/s(x)$ of valence strange quark, and $\Delta u(x)/u(x)$ of valence up and down quarks of the $\Lambda$ are given from the quark-diquark model and from a pQCD based model. It is found that the up and down quarks are positively polarized at large $x$, even though their net spin contributions to the $\Lambda$ might be zero or negative. The significant difference for $u(x)/s(x)$ between the two different approaches are predicted. The prediction of positively polarized up and down quarks inside the $\Lambda$ at large $x$ has been supported by the available data of $\Lambda$-polarization in $Z$ decays and also by the most recent HERMES result of spin transfer to the $\Lambda$ in deep elastic scattering of polarized lepton on the nucleon target.

arXiv comment13 latex pages, one figure added, three eps figures, abstract and discussions changed, prediction comparison with new experimental data added, version to appear in PLB

References in corpus (15)

• QCD Constrains on the Shape of Polarized Quark and Gluon Distributions
• Flavor Asymmetry of Antiquark Distributions in the Nucleon
• The Quark/Antiquark Asymmetry of the Nucleon Sea
• Neutron/Proton Structure Function Ratio at Large x
• Parton Distributions, d/u, and Higher Twist Effects at High X
• Polarized $q\to \Lambda$ Fragmentation Functions from $e^{+}{e}^{-}\to \Lambda +X^{\ast }$
• Polarized Lambdas in the Current Fragmentation Region
• The Proton Spin and the Wigner Rotation
• Status of the Proton Spin Problem
• Spin content of Lambda and its longitudinal polarization in $e^{+}{e}^{-}$ annihilation at high energies
• Lambda and Lambda-bar Polarization in Lepton Induced Processes
• Quark Structure of $\Lambda$ from $\Lambda$-Polarization in Z Decays
• Quark Flavor Separation in $\Lambda$-Baryon Fragmentation
• The strange quark spin of the proton in semi-inclusive $\Lambda$ leptoproduction
• Asymmetric Quark/Antiquark Hadronization in e+e- Annihilation

Cited by in corpus (38)

• The Flavor and Spin Structure of Hyperons from Quark Fragmentation
• Measurement of the Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons in Polarised Muon DIS
• Nucleon Transversity Distribution from Azimuthal Spin Asymmetry in Pion Electroproduction
• Measurement of Longitudinal Spin Transfer to Lambda Hyperons in Deep-Inelastic Lepton Scattering
• Longitudinal Spin Transfer to the $\Lambda$ Hyperon in Semi-Inclusive Deep-Inelastic Scattering
• Leading and higher twist contributions in semi-inclusive e+e- annihilation at high energies
• Tensor polarization dependent fragmentation functions and e+e-\to V πX at high energies
• Helicity and Transversity Distribution of Nucleon and $\Lambda$-Hyperon from $\Lambda$ Fragmentation
• Quark Distributions of Octet Baryons from SU(3) Symmetry
• Statistical approach for unpolarized fragmentation functions for the octet baryons
• Connection between Distribution and Fragmentation Functions
• Basis light-front quantization approach to $\Lambda$ and ${\Lambda }_c$ and their isospin triplet baryons
• Energy dependence of hadron polarization in $e^{+}{e}^{-}\to hX$ at high energies
• Sea quark contents of octet baryons
• The Spin Alignment of Vector Mesons in High Energy pp Collisions
• Spin Transfers for Baryon Production in Polarized pp Collisions at RHIC-BNL
• Several Topics on Transverse Momentum-Dependent Fragmentation Functions
• Probing the longitudinal spin transfer via dihadron polarization correlations in unpolarized $e^{+}{e}^{-}$ and $pp$ collisions
• Up and Down Quark Contributions to Spin Content of Lambda from Fragmentation
• Quark to $\Lambda$-hyperon spin transfers in the current-fragmentation region
• The Quark-Antiquark Asymmetry of the Nucleon Sea from $\Lambda$ and $\bar{\Lambda }$ Fragmentation
• $q\to \Lambda$ Fragmentation Function and Nucleon Transversity Distribution in a Diquark Model
• Quark Fragmentation Functions in a Diquark Model for $\Lambda$ Production
• Phenomenological Relation between Distribution and Fragmentation Functions
• EMC effect in semi-inclusive deep-inelastic scattering process
• Strange quark-antiquark asymmetry of nucleon sea from $\Lambda /\bar{\Lambda }$ polarization
• Nucleon strangeness polarization from $\Lambda /\bar{\Lambda }$ hyperon production in polarized proton-proton collision at RHIC
• Estimations of ${\bar{\Omega }}^{+}/{\Omega }^{-}$ at RHIC from a QGP Model with Diquarks
• Predicting the $\sin {\varphi }_S$ Single-Spin-Asymmetry of $\Lambda$ Production off transversely polarized nucleon in SIDIS
• Ratio of $\bar{\Lambda }/\Lambda$ in Semi-inclusive Electroproduction
• Hadronization Approach for a Quark-Gluon Plasma Formed in Relativistic Heavy Ion Collisions
• Production Ratios of Strange Baryons from QGP with Diquarks
• Nuclear EMC effect through $\bar{\Lambda }/\Lambda$ production in semi-inclusive deep-inelastic scattering processes
• Evidence for SU(3) symmetry breaking from hyperon production
• Transverse spin polarization as a novel probe of medium-induced transverse-momentum-broadening effect
• Particle-Antiparticle Asymmetries of $\Lambda$ Production in Hadron-Nucleon Collisions
• Status of Spin Physics - Experimental Summary
• Mass Suppression in Octet Baryon Production