Related papers: A lattice study of the spin structure of the Lambd…
We investigate the spin structure of the pion within the framework of the nonlocal chiral quark model from the instanton vacuum. We first evaluate the tensor form factors of the pion for the first and second moment (n=1,2) and compare it…
The large statistics of millions of hadronic Z0 decays, accumulated by the four LEP experiments between 1989 and 1995, allowed for detailed investigations of the fragmentation process. Inclusive Lambda_b baryons and Lambda hyperons at…
The effects of $\bar\Lambda\bar\Lambda\omega$-tensor coupling on the spin symmetry of $\bar{\Lambda}$ spectra in $\bar{\Lambda}$-nucleus systems have been studied with the relativistic mean-field theory. Taking $^{12}$C+$\bar{\Lambda}$ as…
Inclusive and semi-inclusive deep inelastic leptoproduction offers possibilities to study details of the quark and gluon structure of hadrons. In many of these experiments polarization is an essential ingredient. We also emphasize the…
Lattice formulations of QCD with Wilson fermions and a chirally twisted quark mass matrix provide an attractive framework for non-perturbative numerical studies. Owing to reparameterization invariance, the limiting continuum theory is just…
As a direct source of information on chiral symmetry breaking within QCD, the sigma commutator is of considerable importance. Since hadron structure is a non-perturbative problem, numerical calculations on a space-time lattice are currently…
We make a quenched lattice simulation of hadron spectroscopy at beta=6.2 with the Wilson action non-perturbatively improved. With respect to the unimproved case, the estimate of the lattice spacing is less influenced by the choice of input…
Treating baryons as quark + interacting-diquark bound states, a symmetry-preserving formulation of a vector$\,\times\,$vector contact interaction (SCI) is used to deliver an extensive, coherent set of predictions for $\Lambda, \Sigma^0$…
Isospin breaking effects in baryon octet (and decuplet) masses are due to a combination of up and down quark mass differences and electromagnetic effects and lead to small mass splittings. Between the Sigma and Lambda this mass splitting is…
Spin-1 hadrons contain different aspects of spin physics from the ones of the spin-1/2 nucleon because of the existence of tensor-polarized structure functions. In the charged-lepton deep inelastic scattering from a spin-1 hadron or…
We show that most features of the mass and mixing pattern of the second and third SM fermion families can be accounted for without making use of flavour symmetries or other types of flavour dynamics. We discuss the implications for flavour…
We study the impact of explicit chiral symmetry breaking of lattice Wilson fermions on mesonic correlators in the epsilon-regime using Wilson chiral perturbation theory. We generalize the epsilon-expansion of continuum chiral perturbation…
After the initial discovery of the so-called "spin crisis in the parton model" in the 1980's, a large set of polarization data in deep inelastic lepton-nucleon scattering was collected at labs like SLAC, DESY and CERN. More recently, new…
The masses of the negative parity 70-plet baryons are analyzed in large N_c QCD to order 1/N_c and to first order in SU(3) symmetry breaking. The existing experimental data are well reproduced and twenty new observables are predicted. The…
We study the structure of pairing order parameter for spin-1/2 fermions with attractive interactions in a square lattice under a uniform magnetic field. Because the magnetic translation symmetry gives a unique degeneracy in the…
We study fermions in a lattice, with on-site and nearest neighbor attractive interactions between two spin species. We consider two geometries: both spins in a triangular lattice, and a mixed geometry with up-spins in honeycomb and…
The $\Lambda(1405)$ baryon is difficult to detect in experiment, absent in many quark model calculations, and supposedly manifested through a two-pole structure. Its uncommon properties made it subject to numerous experimental and…
We study inclusive Lambda hyperon production in pp collisions at BNL RHIC, with just one transversely polarized proton. We show that the measurement of the spin transfer between the initial proton and the produced Lambda is sensitive to the…
Recent developments in lattice QCD calculation of flavor singlet nucleon matrix elements are reviewed. Substantial sea quark contributions are found in the $\pi$-$N\ \sigma$ term and the quark spin content of the nucleon such that the total…
The question how the spin of the nucleon is distributed among its quark and gluon constituents is still a subject of intense investigations. Lattice QCD has progressed to provide information about spin fractions and orbital angular momentum…