0000000000084309
AUTHOR
Humberto Garcilazo
Constituent quark model study of light- and strange-baryon spectra
We investigate the structure of the SU(3) octet and decuplet baryons employing a constituent quark model designed for the study of the baryon-baryon interaction and successfully applied to the meson spectra. The model considers through the interacting potential perturbative, one-gluon exchange, and non-perturbative, boson exchanges and confinement, aspects of the underlying theory, QCD. We solve the three-quark problem by means of the Faddeev method in momentum space. We analyze the effect of the different terms in the interaction and make contact with the use of relativistic kinematics. We find an explanation to the strong contribution of the pseudoscalar forces in the semirelativistic app…
A SU(4) circle times O(3) scheme for nonstrange baryons
4 pages, 3 tables.-- PACS nrs.: 12.39.Jh, 14.20.-c, 14.20.Gk.-- ISI Article Identifier: 000245667300027.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ph/0610257
Strange tribaryons
We use two-body potentials derived from a constituent quark cluster model to analyze the bound-state problem of the $\Sigma NN$ system. The observables of the two-body subsystems, $NN$ and $\Sigma N$, are well reproduced. We do not find $\Sigma NN$ bound states, but there are two attractive channels with a resonance close above the three-body threshold. These channels are the $(I,J)=(1,1/2)$ and $(0,1/2)$, their quantum numbers, widths and energy ordering consistent with the recently measured strange tribaryons from the $^{4}{\rm He}(K_{{\rm stopped}}^{-},N)$ reactions in the KEK PS E471 experiment.
Maximal isospin few-body systems of nucleons and $\Xi$ hyperons
By using local central Yukawa-type interactions that reproduce the low-energy parameters of the latest updates of the Nijmegen ESC08c potentials we show that the $N\Xi$, $NN\Xi$, $N\Xi\Xi$ and $NN\Xi\Xi$ systems with maximal isospin are bound. Since in these states the strong decay $N\Xi\to\Lambda\Lambda$ is forbidden by isospin conservation, these strange few-body systems will be stable under the strong interaction. These results may suggest that other states with different number of $N$'s and $\Xi$'s in the maximal isospin channel could also be bound.
Constituent-quark model description of triply heavy-baryon nonperturbative lattice QCD data
This paper provides results for the spectra of triply charmed and bottom baryons based on a constituent quark model approach. We take advantage of the assumption that potential models are expected to describe triply heavy baryons to a similar degree of accuracy as the successful results obtained in the charmonium and bottomonium sectors. The high precision calculation of the ground state and positive and negative parity excited states recently reported by nonperturbative lattice QCD provides us with a unique opportunity to confront model predictions with data. This comparison may also help to build a bridge between two difficult to reconcile lattice QCD results, namely, the lattice SU(3) QC…
QCD Confinement and the Meson Spectrum
From QCD and lattice calculations two specific forms of quark confining potential, a strict linear and a screened linear confinement, come out. Both forms of the potential, implemented by the one gluon exchange interaction, are applied to the description of heavy quarkonia: cc and bb. Applications to light hadrons, mesons and baryons, are also commented.
Symmetry patterns in the (N, Delta) spectrum
We revise the role played by symmetry in the study of the low-lying baryon spectrum and comment on the difficulties when trying to generalize the symmetry pattern to higher energy states. We show that for the $(N,\Delta)$ part such a generalization is plausible allowing the identification of spectral regularities and the prediction of until now non-identified resonances.
Doubly heavy baryon spectra guided by lattice QCD
This paper provides results for the ground state and excited spectra of three-flavored doubly heavy baryons, $bcn$ and $bcs$. We take advantage of the spin-independent interaction recently obtained to reconcile the lattice SU(3) QCD static potential and the results of nonperturbative lattice QCD for the triply heavy baryon spectra. We show that the spin-dependent potential might be constrained on the basis of nonperturbative lattice QCD results for the spin splittings of three-flavored doubly heavy baryons. Our results may also represent a challenge for future lattice QCD work, because a smaller lattice error could help in distinguishing between different prescriptions for the spin-dependen…
Heavy baryon spectroscopy with relativistic kinematics
We present a comparative Faddeev study of heavy baryon spectroscopy with nonrelativistic and relativistic kinematics. We show results for different standard hyperfine interactions with both kinematics in an attempt to learn about the light quark dynamics. We highlight the properties of particular states accessible in nowadays laboratories that would help in discriminating between different dynamical models. The advance in the knowledge of light quark dynamics is a key tool for the understanding of the existence of exotic hadrons.
Quark-model study of the hadron structure and the hadron-hadron interaction
Recent results of hadron spectroscopy and hadron-hadron interaction within a quark model framework are reviewed. Higher order Fock space components are considered based on new experimental data on low-energy hadron phenomenology. The purpose of this study is to obtain a coherent description of the low-energy hadron phenomenology to constrain QCD phenomenological models and try to learn about low-energy realizations of the theory.
ΛNNandΣNNsystems at threshold. II. The effect ofDwaves
Using the two-body interactions obtained from a chiral constituent quark model, we study allN N andN N states with I = 0, 1, 2a ndJ = 1/2, 3/2 at threshold, taking into account all three-body configurations with S and D wave components. We constrain further the limits for theN spin-triplet scattering length a1/2,1 .U sing the hypertriton binding energy, we find a narrow interval for the possible values of theN spin-singlet scattering length a1/2,0. We find that theN N system has a quasibound state in the (I,J ) = (1, 1/2) channel very near threshold with a width of about 2.1 MeV.
Heavy-baryon quark model picture from lattice QCD
The ground state and excited spectra of baryons containing three identical heavy quarks, $b$ or $c$, have been recently calculated in nonperturbative lattice QCD. The energy of positive and negative parity excitations has been determined with high precision. Lattice results constitute a unique opportunity to learn about the quark-confinement mechanism as well as elucidating our knowledge about the nature of the strong force. We analyze the nonperturbative lattice QCD results by means of heavy-quark static potentials derived using SU(3) lattice QCD. We make use of different numerical techniques for the three-body problem.
Effect of higher orbital angular momenta in the baryon spectrum
We have performed a Faddeev calculation of the baryon spectrum for the chiral constituent quark model including higher orbital angular momentum states. We have found that the effect of these states is important, although a description of the baryon spectrum of the same quality as the one given by including only the lowest-order configurations can be obtained. We have studied the effect of the pseudoscalar quark-quark interaction on the relative position of the positive- and negative-parity excitations of the nucleon as well as the effect of varying the strength of the color-magnetic interaction.
b(b)over-bar description with a screened potential
Recent lattice QCD calculations suggest a rather abrupt transition in the confinig potential from a linear to a constant behavior. We analyze the effects of such a fast deconfinement in the simplest non-relativistic system, bottomonium.