Related papers: Is There a Third Companion of Lambda and Sigma0?
We check the $u$ and $d$ quark contributions to the spin content of the $\Lambda$ by means of the $q\to\Lambda$ fragmentation and find that the $u$ and $d$ quarks of the $\Lambda$ are likely positively polarized. The parton distributions in…
Quarks, leptons and heavy vector bosons are suggested to be composed of stable spin-1/2 preons, existing in three flavours, combined according to simple rules. Straightforward consequences of an SU(3) preon-flavour symmetry are the…
We study baryons as three-body systems using the QCD degrees of freedom in the framework of covariant Bethe-Salpeter equations. The interaction among quarks is reduced to a vector-vector interaction via a single dressed-gluon exchange…
We describe our recent lattice study of SU(4) gauge theory with fermions in the fundamental and sextet representations. In this theory, a new type of baryon consists of quarks in both representations. The spectrum of these "chimera baryons"…
We calculate saturation curves for strange hadron matter using recently constructed baryon-baryon potentials which are constrained by SU(3) symmetry. All possible interaction channels within the baryon octet (consisting of $N$, $\Lambda$,…
We study baryons on the lattice with a special focus on excited states. For that purpose we construct several interpolators which differ in their Dirac structure. These interpolators are built from Jacobi smeared quarks with different…
Experimental data on electromagnetic and weak form factors of the nucleon are analyzed in a two-component model with a quark-like intrinsic structure surrounded by a meson cloud. The contribution from strange quarks is discussed and…
The possible candidates of $S-$wave dibaryons with various strange numbers are studied under the chiral SU(3) quark model. It is shown that there are three types of baryon-baryon bound states. The states of the first type are called…
In these lecture notes I discuss an algebraic model of baryons and pentaquarks, in particular a stringlike collective model is considered in which the radial excitations of baryons and pentaquarks are interpreted as rotations and vibrations…
The spectrum of the $c qq$ baryons contains a few states whose nature is not clearly a three-quark composite and which might have a sizable baryon-meson component. Examples include the $\Sigma_c(2800)$ or the $\Lambda_c(2940)$. Here we…
The newly observed $\Theta^+$ resonance is believed to be a pentaquark with the constituent quarks $uudd\bar s$. There are a few options for the constituent quark structure. Some advocate diquark-diquark-antiquark $(ud)$-$(ud)$-$\bar s$…
Some short history of few-body methods originated from the famous Skornyakov-Ter-Martirosyan equation is given, including latest development of Faddeev formalism and Efimov states. The 3q system is shown to require an alternative, which is…
We consider the thermodynamics of the matter made up of equal number of neutrons and protons and of scalar dibaryons. They interact via the exchange of scalar and vector mesons. The interaction is taken into account in the mean field…
Highlights from recent computations in lattice QCD involving baryons are presented. Calculations of the proton mass and spin decompositions are discussed, a percent level determination of the nucleon axial coupling is described, and…
A diquark model is used to investigate single charmed baryons. In this model, baryon is composed of two diquarks and an antiquark. Masses of lowest lying states with $J^P= 1/2 ^ \pm$ are obtained. Some masses are smaller than other…
Baryons are treated as three-quark systems using QCD degrees of freedom in Poincare-covariant bound-state equations. The quark self-energy as well as the interaction between quarks are approximated by a vector-vector interaction via a…
We treat the baryon as a composite system made out of a \lq\lq core" of three quarks (as in the standard quark model) surrounded by a \lq\lq sea" (of gluons and $q\bar{q}$-pairs) which is specified by its total quantum numbers like flavor,…
Based on the fact that the constituent quark model reproduces the recent lattice result on baryon-baryon repulsion at short distance and that it includes the quark dynamics with confinement, we analyze to what extent the quarkyonic modes…
Using the approximate flavor SU(3) symmetry of strong interactions, we argue for the existence of a new Lambda baryon with J^P=3/2^-, the mass around 1850 MeV, the total width of about 130 MeV, significant branching into the Sigma \pi and…
The possibility of interpreting baryons containing a single heavy quark as bound states of solitons (that arise in the nonlinear sigma model) and heavy mesons is explored. Particular attention is paid to the parity of the bound states and…