Related papers: $\Lambda (1405)$ from lattice QCD
We present a study of baryon ground states and low lying excitations of non-strange and strange baryons. The results are based on seven gauge field ensembles with two dynamical light Chirally Improved (CI) quarks corresponding to pion…
Highly excited states for isospin 1/2 baryons are calculated for the first time using lattice QCD with two flavors of dynamical quarks. Anisotropic lattices are used with two pion masses: 416(36) MeV and 578(29) MeV. The lowest four…
We apply the method of the QCD sum rule, in which positive- and negative-parity baryons couple with each other, to the flavor-octet hyperons and investigate the parity splittings. We also reexamine the nucleon in the method, which was…
We study the possibility that four iso-singlet baryons $\Lambda_s(1405)$ $J^P=1/2^{-}$, $\Lambda_s(1520)$ $J^P=3/2^{-}$, $\Lambda_c(2593)$ $J^P=1/2^{-}$ and $\Lambda_c(2625)$ $J^P=3/2^{-}$ are hybrids: three quark one gluon states (udsg).…
We discuss the extraction of negative-parity baryon masses from lattice QCD calculations. The mass of the lowest-lying negative-parity $J = 1/2^{-}$ state is computed in quenched lattice QCD using an ${\cal O}(a)$-improved clover fermion…
Magnetic moments of the octet baryons are computed using lattice QCD in background magnetic fields, including the first treatment of the magnetically coupled Sigma-Lambda system. Although the computations are performed for relatively large…
We present further data in search of a parity-flavor-breaking phase in simulations of dynamical QCD with two flavors of light Wilson fermions in the strong coupling region. This is done on lattice sizes of 4^4 an up to 10^4 for a variety of…
We present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using…
We present the first lattice-QCD determination of the form factors describing the semileptonic decays $\Lambda_b \to \Lambda_c^*(2595)\ell^-\bar{\nu}$ and $\Lambda_b \to \Lambda_c^*(2625)\ell^-\bar{\nu}$, where the $\Lambda_c^*(2595)$ and…
The pole structure of the $\Lambda(1405)$ has been a topic of debate for a long time. Chiral perturbation theory predicts that its experimental spectrum may be explained by a two pole structure originating in the $SU(3)$ chiral dynamics of…
We evaluate the $\pi N!N$, $\pi\Sigma\Sigma$, $\pi\Lambda\Sigma$, $K\Lambda N$ and $K \Sigma N $ coupling constants and the corresponding monopole masses in lattice QCD with two flavors of dynamical quarks. The parameters representing the…
The masses of the negative parity 70-plet baryons are analyzed in large N_c QCD to order 1/N_c and to first order in SU(3) symmetry breaking. The existing experimental data are well reproduced and twenty new observables are predicted. The…
The mass of the lowest spin-zero, strangeness-$(-2)$ flavor singlet state in the dibaryon sector has been calculated in quenched QCD on $16^3\times32$ and $24^3\times32$ lattices at $\beta=5.85$ to study whether the energy of the proposed…
We report the results of lattice numerical studies of the Sp(4) gauge theory coupled to fermions (hyperquarks) transforming in the fundamental and two-index antisymmetric representations of the gauge group. This strongly-coupled theory is…
We determine the ground state and first excited state masses of singly and doubly charmed spin 1/2 and 3/2 baryons with positive and negative parity. Configurations with $N_f=2+1$ non-perturbatively improved Wilson-clover fermions were…
The electromagnetic properties of the SU(3)-flavor baryon decuplet are examined within a lattice simulation of quenched QCD. Electric charge radii, magnetic moments, and magnetic radii are extracted from the E0 and M1 form factors.…
A recent lattice calculation of the QCD running coupling is presented. The coupling is extracted from the force between two static quarks in the framework of the valence quark approximation. A value of the Lambda-parameter for zero quark…
We study the spin $\frac12$ hadronic state in quenched lattice QCD to search for a possible $S=+1$ pentaquark resonance. Simulations are carried out on $8^3\times 24$, $10^3\times 24$, $12^3\times 24$ and $16^3\times 24$ lattices at…
We propose S=+1 baryon interpolating operators, which are based on an exotic description of the antidecuplet baryon like diquark-diqaurk-antiquark. By using one of the new operators, the mass spectrum of the spin-1/2 pentaquark states is…
Masses of positive and negative parity excited nucleons and hyperons are calculated in quenched lattice QCD using an O(a^2) improved gluon action and a fat-link clover fermion action in which only the irrelevant operators are constructed…