相关论文: Negative-Parity Baryon Spectroscopy
We present a calculation of the mass of the lowest-lying negative-parity J=1/2- state in quenched QCD. Results are obtained using a non-perturbatively O(a)-improved clover fermion action, and a splitting is found between the mass of the…
Using the constrained-fitting method based on Bayesian priors, we extract the masses of the two lowest states of octet and decuplet baryons with both parities. The calculation is done on quenched 16^3x28 lattices of a=0.2 fm using an…
The negative and positive parity low-spin states of the even-odd Tungsten isotopes, 183,185,187W are studied in the frame work of the Interacting Boson-Fermion Approximation (IBFA) model. The fermion that is coupled to the system of bosons…
We have investigated the negative-parity states and electromagnetic transitions in $^{151,153}$Ho and $^{151,153}$Dy within the framework of the interacting boson fermion model 2 (IBFM-2). Spin assignments for some states with uncertain…
From recent study of properties of the lowest spin-parity $1/2^-$ baryons, $N^*(1535)$ and $\Delta^*(1620)$, new pictures for the internal structure of the lowest $1/2^-$ baryon octet and decuplet are proposed. While the lowest $1/2^-$…
A global study of the negative parity non-strange baryon observables is performed in the frame- work of the 1/Nc expansion. Masses, partial decay widths and photo-couplings are simultaneously analyzed. A main objective is to determine the…
There exist candidates for the negative-parity states $\Lambda_{c,b}(1/2^-, 3/2^-)$ consisting of an isospin-zero, spin-zero light diquark $[ud]$ with one unit of orbital angular momentum with respect to a $c,b$ quark. However, there exists…
The recently-introduced Parity Expanded Variational Analysis (PEVA) technique allows for the isolation of baryon eigenstates at finite momentum free from opposite-parity contamination. In this paper, we establish the formalism for computing…
We present first results for the masses of positive and negative parity excited baryons calculated in lattice QCD using an O(a^2)-improved gluon action and a fat-link irrelevant clover (FLIC) fermion action in which only the irrelevant…
We discuss topological aspects of the electroweak sphaleron and its odd-parity deformations. We demonstrate that they are uniquely classified in terms of their odd and even-parity pure gauge field behaviour at spatial infinity. Fermion…
Corrections to the masses of baryons from baryon-meson loops can induce splittings between baryons which are comparable to those arising from the residual interactions between the quarks. These corrections are calculated using a…
Octupole deformation and the relevant spectroscopic properties of neutron-rich odd-mass barium isotopes are investigated in a theoretical framework based on nuclear density functional theory and the particle-core coupling scheme. The…
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…
The recently postulated existence of a baryon antidecuplet [1] can be reproduced in strong coupling theory in which a bare baryon spin 1/2 octet interacts with an octet of pseudoscalar mesons. When a suitable mixture of F- and D-type Yukawa…
We study baryons on the lattice with a special focus on excited states. For that purpose we construct several interpolators which differ in their Dirac structure. These interpolators are built from Jacobi smeared quarks with different…
The negative-parity ground state of the \Lambda{} baryon lies surprisingly low in mass. At 1405.1 MeV, it lies lower than the negative-parity ground state nucleon, even though it has a valence strange quark. Using the PACS-CS (2+1)-flavour…
We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T-matrix for meson-baryon scattering in s-wave. The building blocks of the scheme are the pion and…
Heavy even-even nuclei exhibit low-energy collective excitations that are separated in scale from the microscopic (fermion) degrees of freedom. This separation of scale allows us to approach nuclear vibrations within an effective field…
The gross features of the observed baryon excitation spectrum below 2 GeV are well explained if the spectrum generating algebra of its intrinsic orbital angular momentum states is o(4)*su(2)_I. The spins of the resonances are obtained…
The present study provides spectroscopic investigations of spin-$\frac{3}{2}$ $\Lambda$ baryons with both positive and negative parities. The analysis mainly focuses on three states, namely $1P$, $2P$, and $2S$, and corresponding masses are…