253 research outputs found

    Loosely bound hyperons in the SU(3) Skyrme model

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    Hyperon pairs bound in deuteron like states are obtained within the SU(3) Skyrme model in agreement with general expectations from boson exchange models. The central binding from the flavor symmetry breaking terms increases with the strangeness contents of the interacting baryons whereas the kinetic non-linear σ\sigma-model term fixes the spin and isospin of the bound pair. We give a complete account of the interactions of octet baryons within the product approximation to baryon number B=2B=2 configurations.Comment: 35 pages REVTEX including 2 figs, with 3 further figs available on request from [email protected] or from [email protected] SI-94-TP3S2; STPHY-Th/94-

    On the quantization of SU(3)-skyrmions

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    The quantization condition derived previously for SU(2) solitons quantized with SU(3)-collective coordinates is generalized for SU(3) skyrmions with strangeness content different from zero. Quantization of the dipole-type configuration with large strangeness content found recently is considered as an example.Comment: 7 pages, 2 figures (available by request

    Flavor symmetry breaking effects on SU(3) Skyrmion

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    We study the massive SU(3) Skyrmion model to investigate the flavor symmetry breaking (FSB) effects on the static properties of the strange baryons in the framework of the rigid rotator quantization scheme combined with the improved Dirac quantization one. Both the chiral symmetry breaking pion mass and FSB kinetic terms are shown to improve cc the ratio of the strange-light to light-light interaction strengths and cˉ\bar{c} that of the strange-strange to light-light.Comment: 12 pages, latex, no figure

    Semiclassical quantization of SU(3) skyrmions

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    Semiclassical quantization of the SU(3)-skyrmions is performed by means of the collective coordinate method. The quantization condition known for the SU(2)-solitons quantized with SU(3) collective coordinates is generalized for the SU(3) skyrmions with strangeness content different from zero. Quantization of the dipole-type configuration with large strangeness content found recently is considered as an example, the spectrum and the mass splitting of the quantized states are estimated. The energy and baryon number density of SU(3) skyrmions are presented in the form emphasizing their symmetry in different SU(2) subgroups of SU(3), and the lower boundary for the static energy of SU(3) skyrmions is derived.Comment: 16 pages, 2 figures (available upon request). Submitted to JETP on May 6, 1997; in print. A preliminary short version of this paper is hep-th/960916

    Fluctuation properties of strength functions associated with giant resonances

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    We performed fluctuation analysis by means of the local scaling dimension for the strength function of the isoscalar (IS) and the isovector (IV) giant quadrupole resonances (GQR) in 40^{40}Ca, where the strength functions are obtained by the shell model calculation within up to the 2p2h configurations. It is found that at small energy scale, fluctuation of the strength function almost obeys the Gaussian orthogonal ensemble (GOE) random matrix theory limit. On the other hand, we found a deviation from the GOE limit at the intermediate energy scale about 1.7MeV for the IS and at 0.9MeV for the IV. The results imply that different types of fluctuations coexist at different energy scales. Detailed analysis strongly suggests that GOE fluctuation at small energy scale is due to the complicated nature of 2p2h states and that fluctuation at the intermediate energy scale is associated with the spreading width of the Tamm-Dancoff 1p1h states.Comment: 14 pages including 13figure

    Mass and width of the dd' resonance in nuclei

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    We calculated the mass and width of the dd' resonance inside nuclei within a nucleon-Δ\Delta model by including the self-energy of the Δ\Delta in the NΔN\Delta propagator. We found that in the nuclear medium the width of the dd' is increased by one order of magnitude while its mass changes only by a few MeV. This broadening of the width of the dd' resonance embedded in nuclei is consistent with the experimental observations so that the dd' can be understood as a NΔN\Delta resonance. Thus, given the freedom between either isospin 0 or isospin 2 for the dd', our results give weigth to the isospin-2 assignment.Comment: 14 pages, RevteX type, 2 eps figures. To be published in Phys. Rev. C (September

    Hot Nucleons in Chiral Soliton Models

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    Chiral lagrangians as effective field theories of QCD are most suitable for the study of nucleons in a hot pion gas because they contain pions and also baryons as solitons of the same action. The semiclassical treatment of the soliton solutions must be augmented by pionic fluctuations which requires renormalisation to 1-loop, and finite temperatures do not introduce new ultraviolet divergencies and may easily be considered. Alternatively, a renormalisation scheme based on the renormalisation group equation at finite temperature comprises and extends the rigorous results of chiral perturbation theory and renders the low energy constants temperature-dependent which allows the construction of temperature-dependent solitons below the critical temperature. The temperature-dependence of the baryon energy and the pion-nucleon coupling is studied. There is no simple scaling law for the temperature-dependence of these quantities.Comment: 17 pages (RevTeX), 5 figure

    Twist Mode in Spherical Alkali Metal Clusters

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    A remarkable orbital quadrupole magnetic resonance, so-called twist mode, is predicted in alkali metal clusters where it is represented by Iπ=2I^{\pi}=2^- low-energy excitations of valence electrons with strong M2 transitions to the ground state. We treat the twist by both macroscopic and microscopic ways. In the latter case, the shell structure of clusters is fully exploited, which is crucial for the considered size region (8Ne13148\le N_e\le 1314). The energy-weighted sum rule is derived for the pseudo-Hamiltonian. In medium and heavy spherical clusters the twist dominates over its spin-dipole counterpart and becomes the most strong multipole magnetic mode.Comment: 8 pages, 4 figures, to be published in Phys. Rev. Lett., v.85, n.15, 200

    Role of Light Vector Mesons in the Heavy Particle Chiral Lagrangian

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    We give the general framework for adding "light" vector particles to the heavy hadron effective chiral Lagrangian. This has strong motivations both from the phenomenological and aesthetic standpoints. An application to the already observed D \rightarrow \overbar{K^*} weak transition amplitude is discussed.Comment: 19 pages, LaTeX documen
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