相关论文: Suppression of PiNN* Coupling and Chiral Symmetry
Meson-baryon couplings between positive and negative parity nucleons are investigated using two point correlation functions in the soft meson and the chiral limit. We find that the pi NN* coupling vanishes due to chiral symmetry, while the…
Jido, Oka and Hosaka have shown that the p-slash gamma_5 piece of the pion-to-vacuum correlator of two baryon interpolating fields vanishes in the soft-pion limit, as a consequence of chiral transformation properties of those fields. This…
The \pi NN^* and \eta NN^* coupling constants are studied based on the two point functions between the vacuum and a one meson state in the soft meson limit. In terms of a suitably constructed interpolating field for the nucleon and…
Chiral properties of positive and negative parity nucleons, N and N*$, are studied from the viewpoint of chiral symmetry. Two possible ways to assign chiral transformations to the negative parity nucleon are considered. Using linear sigma…
Using a chiral unitary model in which the negative parity nucleon resonance $N^\ast \equiv N^\ast(1535)$ is generated dynamically by means of the Bethe Salpeter equation with coupled meson baryon channels in the $S = 0$ sector, we have…
The \pi NN^* and \eta NN^* coupling constants are studied in the QCD sum rule ($N^* \equiv N(1535)). We investigate the two point functions between the vacuum and a one meson state in the soft meson limit. The operator product expansion is…
If a baryon field belongs to a certain linear representation of chiral symmetry of $SU(2) \otimes SU(2)$, the axial coupling constant $g_{A}$ can be determined algebraically from the commutation relations derived from the superconvergence…
Baryon resonances with even and odd parity are collectively investigated from the viewpoint of chiral symmetry(ChS). We propose a quartet scheme where Delta's and N^*'s with even and odd parity form a chiral multiplet. This scheme gives…
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…
Chiral symmetry of the 2-dimensional chiral Gross-Neveu model is broken explicitly by a bare mass term as well as a splitting of scalar and pseudo-scalar coupling constants. The vacuum and light hadrons - mesons and baryons which become…
We present a chiral-invariant meson-baryon Lagrangian which describes the interactions of the baryon octet with the lowest-mass meson nonets. The nonlinear realization of the chiral symmetry generates pair-meson interaction vertices. The…
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 strong coupling constants of negative parity heavy baryons belonging to a sextet and antitriplet representations of $SU_f(3)$ with light $\pi$ and $K$ mesons are estimated within the light cone QCD sum rules. It is observed that each…
It is generally thought that pion masses vanish when bare light quark masses $m_q$ vanish. The pions are Nambu-Goldstone bosons of chiral $SU_{A}(2)$ symmetry. We discuss a possibility that even when $m_q=0$, the chiral symmetry is…
We construct an $SU(3)_L \times SU(3)_R$ symmetric chiral effective model which includes parity pair baryon fields. It is assumed that the positive and negative parity baryons in the parity pair have opposite chiral transformation…
The N*(1440) -> N pi pi decay is studied by making use of the chiral reduction formula. This formula suggests a scalar-isoscalar pion-baryon contact interaction which is absent in the recent study of Hern{\'a}ndez et al. The contact…
The coupling constants of K and pi mesons with the octet baryons are studied in light cone QCD sum rules taking into account SU(3)f flavor symmetry breaking effects, but keeping the SU(2) isospin symmetry intact. It is shown that, in the…
The effective restoration of the chiral U(A)(1) symmetry in strong interactions is studied using the linear chiral SU(3)xSU(3) model at finite temperatures. We find that the disappearance of the chiral anomaly causes a considerable change…
From an SU(2)$\otimes $SU(2) chiral quark potential model incorporating spontaneous chiral symmetry breaking the asymptotic $\pi $ and $\sigma $ exchange pieces of the $NN$ potential are generated. From them the $\pi NN$ and $\sigma NN$…
In this two part series a chiral confining model of baryons is used to describe low--lying negative parity resonances $N^*$, $\Delta^*$, $\Lambda^*$ and $\Sigma^*$ in the mean field approximation. A physical baryon in this model consists of…