相关论文: Large-N_c Baryons
The 1/N_c expansion provides a theoretical method for analyzing the spin-flavor symmetry properties of baryons in QCD that is quantitative, systematic and predictive. An exact spin-flavor symmetry exists for large-N_c baryons, whereas for…
The 1/N_c expansion of QCD with N_c=3 has been successful in explaining a wide variety of QCD phenomenology. Here I focus on the contracted spin-flavor symmetry of baryons in the large-N_c limit and deviations from spin-flavor symmetry due…
A systematic expansion in 1/N is constructed for baryons in QCD. Predictions of the 1/N expansion at leading and subleading order for baryon axial current coupling constant ratios such as F/D, baryon masses and magnetic moments are derived.…
The spin-flavor structure of large N baryons is described in the 1/N expansion of QCD using quark operators. The complete set of quark operator identities is obtained, and used to derive an operator reduction rule which simplifies the 1/N…
Using recently-developed diagrammatic techniques, I derive some general results concerning baryons in the $1/N$ expansion, where $N$ is the number of QCD colors. I show that the spin-flavor relations which hold for baryons in the large-$N$…
This talk reviews recent developments in the use of large $N_c$ QCD in the description of baryonic resonances. The emphasis is on the model-independent nature of the approach. Key issues discussed include the spin-flavor symmetry which…
The chiral Lagrangian for baryons is formulated in an expansion in 1/N_c. The chiral Lagrangian implements the contracted spin-flavor symmetry of large-N_c baryons as well as nonet symmetry of the leading planar diagrams. Large-N_c…
The properties of baryons can be computed in a systematic expansion in $1/N_c$, where $N_c$ is the number of colors. Recent results on the axial couplings and masses of baryons (for the case of three flavors) are presented. The results give…
The mass spectrum of the L=1 orbitally excited heavy baryons with light quarks in the spin-flavor symmetric representation is studied by the $1/N_c$ expansion method in the framework of the heavy quark effective theory. The mixing effect…
The generalization of QCD to many colors is not unique; each distinct choice corresponds to a distinct 1/N_c expansion. The familiar 't Hooft N_c -> \infty limit places quarks in the fundamental representation of SU(N_c), while an…
We present a model-independent analysis of the mass spectrum of nonstrange L=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a basis of effective operators that spans the nine observables (seven masses and two…
The baryon mass operator is studied within a combined expansion in $1/N_c$ and perturbative $SU(3)$ flavor symmetry breaking, where $N_c$ denotes the number of quark charges. Flavor projection operators are used to classify the baryon…
The excited baryon masses are analyzed in the framework of the $1/N_c$ expansion using the available physical masses and also the masses obtained in lattice QCD for different quark masses. The baryon states are organized into irreducible…
Two ideas have greatly contributed to our understanding of baryon structure in the framework of Quantum Chromodynamics (QCD). The first, chiral symmetry, received its fundamental justification from QCD and has been developed into the…
Spin-flavor symmetry breaking in the levels of excited Baryons are studied to leading order in the 1/$N_c$ expansion. This breaking occurs at zeroth order. For non-strange Baryons with a single quark excited, it is shown that to first order…
In the large $N_c$ limit of QCD, baryons can be modeled as solitons, for instance, as Skyrmions. This modeling has been justified by Witten's demonstration that all properties of baryons and mesons scale with $N_c^{-1/2}$ in the same way as…
A combined expansion in the number of QCD colors 1/N_c and SU(3) flavor breaking parameter epsilon has long been known to provide an excellent accounting for the mass spectrum of the lightest spin-1/2, 3/2 baryons when the quarks are taken…
We derive a set of consistency conditions for the pion-baryon coupling constants in the large-N limit of QCD. The consistency conditions have a unique solution which are precisely the values for the pion-baryon coupling constants in the…
Using group theory arguments we extend and complete our previous work by deriving all SU(6) exact wave functions associated to the spectrum of mixed symmetric baryon states $[N_c-1,1]$ in the $1/N_c$ expansion. The extension to SU(6)…
We present a model-independent analysis of the mass spectrum of nonstrange l=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a basis of effective operators that spans the nine observables (seven masses and two…