[en] The quark delocalization and color screening model is used for a systematic study of the effective potential between baryons in the u, d and s sector. The model is constrained by the properties of baryons and N-N scattering. The effective potentials for the N-N (IJ = 01, 10, 11, 00) channels and the N-Λ and N-Σ (IJ = (1(2))1, (1(2))0, (3(2))0) channels fit the N-N, N-Λ and N-Σ scattering data reasonably well. This model predicts: there are rather strong effective attractions between some decuplet-baryons; the effective attractions between octet-baryons are usually weak; and the attractions between decuplet- and octet-baryons lie in between

[en] Implications of few-body hypernuclei for our understanding of the baryon- baryon interaction are examined. Octet-octet coupling effects not present in conventional, non strange nuclei are the focus. The need to identify strangeness -2 hypernuclei to test model predictions is emphasized. (author)

[en] A unified potential model of baryon–baryon and meson–baryon interactions at low energies is proposed. In this model, the short-range cores which simulate recent lattice QCD calculations are introduced. In baryon–baryon sector, our potentials give a very good agreement with NN and YN scattering data and have very similar behavior to those from the lattice QCD calculations. The π N and KN interactions are also well described in our model. (author)

[en] A recent general analysis of light-baryon isospin splittings is updated and extended to charmed baryons. The measured Σ_c and Ξ_c splittings stand out as being difficult to understand in terms of two-body forces alone. We also discuss heavy-light mesons; though the framework here is necessarily less general, we nevertheless obtain some predictions that are not strongly model dependent

[en] The masses of strangeness zero baryons, with quarks in the S, P, and D shells of a harmonic oscillator potential, are calculated in the nonrelativistic constituent quark model. While the color hyperfine interaction is known to be successful in describing the mass splittings, inclusion of pion exchanges markedly improve the mass predictions of nucleon resonances, particularly those of negative parity. Fitting to all well established non-strange baryon masses below ≅ 2 GeV/c² significantly improves previous results. (orig.)

[en] Baryon-baryon coupling such as ΛN-ΣN in Λ hypernuclei and ΛΛ-ΞN in ΛΛ hypernuclei produce novel physics not observed in conventional nonstrange nuclei. This is especially evident in few-body systems. To illustrate this, a comparison of S = -1 and S = 0 baryon-separation energies is made. The role of ΛN-ΣN coupling suppression in the A = 4 Λ hypernuclei due to Pauli blocking is reviewed. The analysis is extended to S = -2 systems. Measurement of the _ΛΛ⁴H or _ΛΛ⁵He ΛΛ separation energy is proposed as a means to investigate the full ΛΛ and ΞN interaction

[en] From the view point of the quantum chromodynamics (QCD) mesons which describe the nuclear forces or baryon-baryon interactions are the qq bound states while the ground states of baryons are 3q states. The baryon-baryon interactions have been studied in detail on the basis of simple quark picture in a natural way by the present authors. For the recent discovery of the pentaquarks, the effects of gluons are considered to be incorporated in the form of interquark potential in the constituent quark model. Numbers of problems to be solved for the pentaquarks on the model are pointed out. Based on the principle that the fundamental interbaryon interactions are to be described in a consistent and unified way by the quark-gluon picture, the baryon-baryon interactions and the nuclear forces are reduced to the flavor dependence of the B₈-B₈ interactions since both the hyperons and nucleons are the members of the B₈ baryon octets in the SU₆. The recent development of this model using fss2 as the baryon interaction gives precise results even better than the phenomenological OBEP model. G-matrix calculations, nuclear matters, single particle potential are discussed on this model. Faddeev calculations of three-nucleon systems with NN interaction, _Λ³H with NN and YN interactions, _ΛΛ⁹Be with ααΛ model, and _ΛΛ⁶He (Nagara event) with ΛΛα model are explained on the quark model. (S. Funahashi)

[en] The effect of in-medium Δ-isobar in strange hadronic matter (SHM) is studied within the framework of the relativistic mean field (RMF). As far as the effect of the in-medium Δ-isobar is concerned, the authors find a second stable state comes into being in the higher density scope in SHM and this effect promotes the producing of Ξ hyperons through the reaction ΛΛ-ΞN. This effect is consistent with the conclusion that Ξ hyperons are constituents of SHM

[en] Based on the flux-tube-breaking mechanism, we have previously studied the strong decay of non-strange baryons into the elastic and several inelastic channels. Here, we extend these studies to Δπ decay. We compare our results with those of Koniuk and Isgur and with recently improved experimental data. We also present results of a new and improved calculation of N π decay and discuss the problem of resonance identification. (orig.)

[en] The symmetric harmonic oscillator quark model for baryons is used to estimate the decay widths of the transitions Σ^* → Σπ, Σ^* → Λπ and Λ^* → Σπ with different possible assignments for Σ^* and Λ^* (excited baryons) in the multiplets [SU (6), l^P]N (N = 1,2) of SU(6) x 0(3). Results are estimated with the standard harmonic oscillator parameter and the quark-pion coupling constant, namely α² = 0.1 Gev² and f²_q/4π ≅ 0.055. Results obtained are compared with the available experimental measurements and the probable [SU(6), l^P]N assignments of the excited strange baryons are assessed. Conclusive classification of the baryons on the basis of this model, can, however, be made on improvement of the experimental data for these widths. (author). 8 refs, 4 tabs