相关论文: Highly excited states of baryons in large $N_c$ QC…
We establish a connection between the quark model and the 1/N_c expansion mass formulas used in the description of baryon resonances. We show that a remarkable compatibility exists between the two methods in the light and heavy baryon…
Previous work is extended from SU(2) to SU(3) and we present results for the mass spectrum of the $[{\bf 70},\ell^+]$ ($\ell=0,2$) nonstrange and strange baryons in the $1/N_c$ expansion. We show that the dominant term is the spin-spin…
QCD string model formulated in the framework of the Field Correlator Method (FCM) in QCD is employed to calculate the masses of $\Sigma_c$, $\Xi_c$ and recently observed at Tevatron $\Sigma_b$, $\Xi_b$ baryons and their orbital excitations.…
A spin-flavor symmetry emerges for baryons in the large-N_c limit. Large-N_c baryons form irreducible representations of the spin-flavor algebra, and their static properties can be computed in a systematic expansion in 1/N_c. Symmetry…
Excited state spectra are calculated using lattice QCD for baryons that can be formed from $u$, $d$ and $s$ quarks, namely the $N$, $\Delta$, $\Lambda$, $\Sigma$, $\Xi$ and $\Omega$ families of baryons. Baryonic operators are constructed…
The spectrum of baryons containing three b quarks is calculated in nonperturbative QCD, using the lattice regularization. The energies of ten excited bbb states with J^P = 1/2^+, 3/2^+, 5/2^+, 7/2^+, 1/2^-, and 3/2^- are determined with…
The discussion of the 70-plet of negative parity baryons illustrates the large Nc QCD approach to orbitally excited baryons. In the case of the l=1 baryons the existing data allows to make numerous predictions to first order in the SU(3)…
We calculate the low-lying spectrum of charmed baryons in lattice QCD on the $32^3\times64$, $N_f=2+1$ PACS-CS gauge configurations at the almost physical pion mass of $\sim 156$ MeV/c$^2$. By employing a set of interpolating operators with…
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…
Our progress in computing the spectrum of excited baryons and mesons in lattice QCD is described. Sets of spatially-extended hadron operators with a variety of different momenta are used. A new method of stochastically estimating the…
This study employs QCD sum rules to predict the masses and residues of spin-$\frac {3}{2} $ doubly heavy baryons including two heavy quarks (c and/or b) and one light quark, specifically focusing on $ \Xi_{cc}^*$, $ \Xi_{bc}^*$, $…
The masses of baryons containing a single heavy quark are studied in a combined expansion in $1/m_Q$, $1/N_c$ and $SU(3)$ flavor symmetry breaking. Heavy quark baryon mass splittings are related to mass splittings of the octet and decuplet…
It is shown that in the large Nc limit heavy baryon masses can be estimated quantitatively in a 1/Nc expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio…
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…
We calculate the masses and residues of triply heavy baryons with spin-3/2, including $\Omega^*_{ccc}$, $\Omega^*_{ccb}$, $\Omega^*_{bbc}$ and $\Omega^*_{bbb}$, using the QCD sum rules method. Our calculations primarily focus on obtaining…
We briefly discuss the large Nc picture for excited baryons, present a new method for the calculation of matrix elements and illustrate it by computing the strong decays of heavy exotic states.
The masses of heavy quark baryons are studied in an expansion in 1/N_c, SU(3) flavor symmetry breaking, and heavy-quark symmetry breaking. Very accurate model-independent mass relations are obtained for charm and bottom baryons.
We determine the masses and residues of the ground and excited spin-$\frac {1}{2} $ baryons consist of two heavy b or c quark utilizing the QCD sum rule formalism. In the calculations, we consider the nonperturbative operators up to ten…
We study excited baryon decay widths in large N_c QCD. It was suggested previously that some spin-flavor mixed-symmetric baryon states have strong couplings of O(N_c^{-1/2}) to nucleons [implying narrow widths of O(1/N_c)], as opposed to…
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…