منابع مشابه
Low lying S = −1 excited baryons and chiral symmetry
The s-wave meson-baryon interaction in the S = −1 sector is studied by means of coupled-channels, using the lowest-order chiral Lagrangian and the N/D method to implement unitarity. The loops are regularized using dimensional renormalization. In addition to the previously studied Λ(1405), employing this chiral approach leads to the dynamical generation of two more s-wave hyperon resonances, the...
متن کاملChiral symmetry in excited baryons
Chiral symmetry is expected to be approximately restored in excited baryons, which is a consequence of quite general symmetry based arguments. However, such a restoration cannot be described in the framework of naive constituent quark models. Then chiral potential quark model (Generalised Nambu-Jona-Lasinio model) is used to draw a microscopic picture of such a restoration: the axial charge ope...
متن کاملLow Lying Scalar Resonances and Chiral Symmetry∗
The σ particle was firstly introduced by Gell-Mann and Levy in association with the linear σ model.1 In such a model, the σ meson develops a non-vanishing vacuum expectation value which triggers the spontaneous breaking of chiral symmetry. Pions act as the (pseudo-)goldstone bosons associated with the spontaneous chiral symmetry breaking (SχSB). In the linear σ model the σ meson fills in the li...
متن کاملExcited Baryons and Chiral Symmetry Breaking of Qcd
There is increasing experimental information on the baryon spectrum from JLab and other accelerators (as tabulated in the particle data group ), and the associated desire to understand it from first principles. The rich structure of the excited baryon spectrum provides a fertile ground for exploring how the internal degrees of freedom in the nucleon are excited and how QCD works in a wider cont...
متن کاملChiral Symmetry of Baryons
We study chiral symmetry aspects of the positive and negative parity baryons by identifying them with linear representations of the chiral group SU(Nf )⊗ SU(Nf ). It is shown that there are two distinctive schemes: naive and mirror assignments. We construct linear sigma models for baryons in the two assignments and examine their physical implications. Then we investigate properties of the naive...
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ژورنال
عنوان ژورنال: Physics Letters B
سال: 2002
ISSN: 0370-2693
DOI: 10.1016/s0370-2693(01)01523-4