Heavy baryons in the relativistic quark model

Lettere al Nuovo Cimento, 1983

We calculate the mass spectrum of heavy baryons as nonrelativistic bound states of three quarks, using phenomenolgical potentials for the quark-quark interactions derived from Q~ effective potentials obtained from fits of the J/~ and families. We solve SchrSdingcr's equation according to)'liigge and Zickendraht's prescription, using a method developed especially for confining potentials. Results arc compared for serveral types of confining potentials.

Physical review, 1975

Relativistic calculations of the I. = 0 energy levels of a qq pair bound by a linear potential are done both for light quarks (the p system) and heavy quarks (charmonium). The suggestion" that the)))(3105) and)))(3695) are bound states of the charmed quark 6" and its antiquark P has revived interest in dynamical calculations of the masses of the qq bound states. Detailed calculations have been done using the nonrelativistic Schrodinger equation with a linear confinement potential for the heavy (6") quarks" and for the light quarks. " For the heavy-quark calculations p posteriori justification of the nonrelativistic calculation was given e.g. by computing the expectation value of P'/m' with the Schrfidinger wave functions and finding that it is small, i.e. , the system is essentially nonrelativistic. Our relativistic calculation confirms this. The light

International Journal of Modern Physics A, 2008

A quark model is applied to the spectrum of baryons containing heavy quarks. The model gives masses for the known heavy baryons that are in agreement with experiment, but for the doubly-charmed baryon Ξcc, the model prediction is too heavy. Mixing between the ΞQ and Ξ′Q states is examined and is found to be small for the lowest lying states. In contrast with this, mixing between the Ξbc and Ξ′bc states is found to be large, and the implication of this mixing for properties of these states is briefly discussed. We also examine heavy-quark spin-symmetry multiplets, and find that many states in the model can be placed in such multiplets. We compare our predictions with those of a number of other authors.

Physical Review C, 2000

Baryons containing two heavy quarks are treated in the Born-Oppenheimer approximation. Schrödinger equation for two center Coulomb plus harmonic oscillator potential is solved by the method of ethalon equation at large intercenter separations. Asymptotical expansions for energy term and wave function are obtained in the analytical form. Using those formulas, the energy spectra of doubly heavy baryons with various quark compositions are calculated analytically.

Physics Letters B, 1994

On the basis of the three-particle Bethe-Salpeter equation we formulated a relativistic quark model for baryons. Assuming the propagators to be given by their free form with constituent quark masses and the interaction kernel by an instantaneous potential, which contains a string-like parameterization of confinement and a flavor dependent interaction motivated by instanton effects we can account for the major features in the baryon spectrum, such as the low position of the Roper resonance and the occurrence of approximate parity doublets apparent in the N-and Λ-spectra.

The European Physical Journal A - Hadrons and Nuclei, 2003

On the basis of the three-particle Bethe-Salpeter equation we formulated a relativistic quark model for baryons. With free constituent-quark propagators and instantaneous interaction kernels a good description of the overall baryonic mass spectrum up to the highest spin states is obtained. Preliminary results on strong two-body decays of baryon resonances are discussed.

The mass spectra for some of the baryon resonances of the particle data group with three-and four-star status are calculated, and a unified description of the ground states and ex-citation spectra of baryons are provided in the framework of a relativistic potential model of independent quarks, taking into account perturbatively the correction due to the one-gluon-exchange interaction along with that due to the Goldstone boson exchange interaction between the constituent quarks and that due to center-of-mass motion. The baryons are assumed here as an assembly of independent quarks confined in a first approximation by an effective square-root potential, which presumably represents the non-perturbative multigluon interactions including gluon self-couplings. The calculated masses of the three-and four-star baryon resonances are found to be in good agreement with the tabulations of the Parti-cle Data Group. The results obtained for the ground states and excitation spectra of the baryons ...

Proceedings of Sixth International Conference on Quarks and Nuclear Physics — PoS(QNP2012)

We report results from a study of light-and heavy-baryon spectra within a relativistic constituent quark model that relies on a universal dynamics for baryons of all flavor contents. The (linear) confinement is taken according to the string tension of quantum chromodynamics and the (flavordependent) hyperfine interaction is derived from an effective Lagrangian resulting from chiralsymmetry breaking. Here, we specifically show results for all baryons that are included in the phenomenological data base of the Particle Data Group with at least three-star status. In general, the spectra are reproduced in good agreement with experiment for both ground and excited states.

The European Physical Journal A, 2001

This is the second of a series of three papers treating light baryon resonances up to 3 GeV within a relativistically covariant quark model based on the three-fermion Bethe-Salpeter equation with instantaneous two-and three-body forces. In this paper we apply the covariant Salpeter framework (which we developed in the first paper [1]) to specific quark model calculations. Quark confinement is realized by a linearly rising three-body string potential with appropriate spinorial structures in Dirac-space. To describe the hyperfine structure of the baryon spectrum we adopt 't Hooft's residual interaction based on QCDinstanton effects and demonstrate that the alternative one-gluon-exchange is disfavored phenomenological grounds. Our fully relativistic framework allows to investigate the effects of the full Dirac structures of residual and confinement forces on the structure of the mass spectrum. In the present paper we present a detailed analysis of the complete non-strange baryon spectrum and show that several prominent features of the nucleon spectrum such as e.g. the Roper resonance and approximate "parity doublets" can be uniformly explained due to a specific interplay of relativistic effects, the confinement potential and 't Hooft's force. The results for the spectrum of strange baryons will be discussed in a subsequent paper [2].