相关论文: Positive and negative-parity flavor-octet baryons …
A new approach of the QCD sum rule is proposed in which positive and negative-parity baryons couple with each other. With positive and negative-parity states explicitly taken into account, sum rules are derived by means of the dispersion…
The masses of the flavor octet and singlet baryons with negative parity and spin 1/2 are calculated using the QCD sum rule. We find that the chiral symmetry breaking vacuum condensates cause the mass splitting of the positive and negative…
QCD sum rules for positive and negative parity heavy baryons in the heavy quark limit are formulated. We apply the method to $\Lambda$ and $\Sigma$ channels. We include the next-to-leading order corrections in $\alpha_s$-expansion to…
The negative-parity baryons are studied by a novel approach in the QCD sum rule. It is found that the parity of the ground-state nucleon is determined by the sign of the quark condensate. We predict the mass of negative-parity nucleon.
Masses and couplings of the negative parity excited baryons are studied in the QCD sum rule. Separation of the negative-parity spectrum is proposed and is applied to the flavor octet and singlet baryons. We find that the quark condensate is…
The nucleon and its negative-parity excited states are examined in a maximum entropy method analysis of QCD sum rules. First, we rederive the parity projected sum rules for baryons using forward correlation functions. Doing this, the method…
We have calculated the mass spectra of nucleon and delta hybrid baryons with both positive-parity and negative-parity by using the method of QCD sum rules. We predicte that the lowest-lying hybrid baryons are the negative-parity $N_{1/2^-}$…
We study the P-wave bottom baryons using the method of QCD sum rule and heavy quark effective theory. Our results suggest that Lambda_b(5912) and Lambda_b(5920) can be well described by the baryon doublet [3F_bar, 1, 1, rho], and they…
New relations between QCD Borel sum rules for masses of Sigma^0 and Lambda hyperons are constructed. It is shown that starting from the sum rule for the Sigma^0 hyperon mass it is straightforward to obtain the corresponding sum rule for the…
We study negative-parity baryon spectra in quenched anisotropic lattice QCD. The negative-parity baryons are measured as the parity partner of the ground-state baryons. In addition to the flavor octet and decuplet baryons, we pay much…
The effects of nuclear medium on the residue, mass and self energy of the positive and negative parity $\Sigma$, $\Lambda$ and $\Xi$ hyperons are investigated using the QCD sum rule method. In the calculations, the general interpolating…
We investigate the electric polarizabilities of neutral baryons using the method of QCD sum rules. The diagrams in the operator product expansion are taken into account up to dimension 6. We obtain different values of the polarizabilities…
Light cone QCD sum rules for the electromagnetic transition form factors among positive and negative parity octet baryons are derived. The unwanted contributions of the diagonal transitions among positive parity octet baryons are eliminated…
Within the method of parity-projected QCD sum rules, we study the mass spectra of light hybrid baryons with $I(J^{P})=1/2(1/2^{\pm}), 3/2(1/2^{\pm}), 1/2(3/2^{\pm}), 3/2(3/2^{\pm})$ by constructing the local $qqqg$ interpolating currents.…
We derive QCD light-cone sum rules for the hadronic matrix elements of the heavy baryon transitions to nucleon. In the correlation functions the $\Lambda_c,\Sigma_c$ and $\Lambda_b$ -baryons are interpolated by three-quark currents and the…
Coupling constants of the pseudoscalar mesons to the octet baryons are calculated in the QCD sum rule approach. Two-point correlation function of the baryons are evaluated in a single meson state and the vacuum, which yields the designated…
In this article, we study the masses and pole residues of the ${1\over 2}^\pm$ flavor antitriplet heavy baryon states ($\Lambda_c^+$, $\Xi_c^+,\Xi_c^0)$ and ($\Lambda_b^0$, $\Xi_b^0,\Xi_b^-)$ by subtracting the contributions from the…
We investigate the negative-parity baryon spectra in quenched lattice QCD. We employ the anisotropic lattice with standard Wilson gauge and O(a) improved Wilson quark actions at three values of lattice spacings with renormalized anisotropy…
The masses of octet baryons are calculated by the method of QCD sum rules. Using generalized interpolating fields, three independent sets of QCD sum rules are derived which allow the extraction of low-lying N* states with spin-parity 1/2+,…
The strong coupling constants of the $\pi$ and $K$ mesons with negative parity octet baryons are estimated within the light cone QCD sum rules. It is observed that all strong coupling constants, similar to the case for the positive parity…