相关论文: Sigma, Kappa, fo(980) and a0(980)

The following topics are considered. 1) Confinement, chiral dynamics, and light scalar mesons. 2) Chiral shielding of the $\sigma(600)$. 3) The $\phi$ meson radiative decays about nature of light scalar resonances. 4) The $J/\psi$ decays…

A critical comparison is made between the ARPES-derived spectral function and STM studies of Friedel-like oscillations in Bi_2Sr_2CaCu_2O_{8+delta} (Bi2212). The data can be made approximately consistent, provided that (a) the elastic…

In present work, we study the reactions $D^{0} \rightarrow K^{+} K^{-} \eta$ and $D^0 \rightarrow \pi^{+} \pi^{-} \eta$, and find that the $a_0(980)$ state plays a dominant role. At the quark level, the external and internal $W$-emission…

Based on $58 \times 10^6 $ $J/\psi$ events collected by BESII, the decay $J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0$ is studied. In the invariant mass spectrum recoiling against the charged $K^*(892)^{\pm}$, the charged $\kappa$ particle is…

A study of three-pseudoscalar $\pi K \bar{K}$ and $\pi \pi \eta$ coupled system is made by solving the Faddeev equations within an approach based on unitary chiral dynamics. A resonance with total isospin one and spin-parity $J^\pi = 0^-$…

An old calculation of the s-wave pi-pi scattering lengths is updated and supplemented with experimental data on the pi-pi s-wave phase shift. The results ma0 = .215 and ma2 = -.039 are in excellent agreement with those obtained from a…

In this work, we have investigated the process $D_s^+\to K^+ K^- \pi^+$, taking into account the contributions from the $S$-wave pseudoscalar-pseudoscalar interaction within the chiral unitary approach, and also the intermediate $\phi$…

An analysis is presented of elastic $P$-wave $\pi\pi$ phase shifts and inelasticities up to 2 GeV, aimed at identifying the corresponding $J^{PC}=1^{--}$ excited $\rho$ resonances and focusing on the $\rho(1250)$ vs. $\rho(1450)$…

The reaction pp -> pf (pi0pi0pi0) ps has been studied at 450 GeV/c. The pi0pi0pi0 effective mass spectrum shows clear eta(547) and pi2(1670) signals. Branching ratios for the eta(547) and pi_2(1670) are given as well as upper limits for the…

We review the use of new and precise dispersive equations, which also implement crossing symmetry, in order to shed further light on the long-standing puzzle in the parameters of the f0(500), as well as the f0(980). This puzzle is finally…

$K\pi$ $S$ wave scattering is studied using a chiral unitary approach (ChUT) taking into account coupled channels. With the amplitudes derived from the lowest order chiral Lagrangian as the kernel of a set of coupled channel Bathe-Salpeter…

We have studied the phi(1020)a0(980) S-wave scattering at threshold energies employing chiral Lagrangians coupled to vector mesons by minimal coupling. The interaction is described without new free parameters by considering the scalar…

On the basis of a simultaneous description of the isoscalar s-wave of $\pi\pi$ scattering (from the threshold up to 1.9 GeV) and of $\pi\pi\to K\bar{K}$ process (from the threshold to $\sim$ 1.4 GeV) in the model-independent approach, it is…

In this talk,we present direct measurements of $a^{0}_{0}(980)-f_{0}(980)$ mixing in the processes $J/\psi\to\phi f_{0}(980)\to\phi a^{0}_{0}(980)\to\phi\eta\pi^{0}$ and $\psi^{\prime}\to\gamma\chi_{c1},\chi_{c1}\to\pi^{0}…

We present for the first time a determination of the energy dependence of the isoscalar $\pi\pi$ elastic scattering phase-shift within a first-principles numerical lattice approach to QCD. Hadronic correlation functions are computed…

The tensor analyzing power $T_{20}$ and the polarization transfer coefficients $\kappa_0 (= 3/2 K_y^y)$ and $K_{xz}^y$ are investigated for dp backward elastic scattering by the invariant-amplitude method. Discrepancies between the…

The results of the experimental study of the reactions e+e-->\pi\pi\gamma, \eta\pi\gamma, \eta'\gamma, \omega\pi,... at VEPP-2M collider with CMD-2 and SND detectors are presented. The branching ratios of \phi, \rho, \omega rare decays were…

We consider the nonleptonic and semileptonic decays of $D_s$-mesons into $\phi$ and $f_0(980)$ mesons. QCD sum rules are used to calculate the form factors associated with these decays, and the correspondig decay rates. On the basis of data…

We have performed two analytical pipi phase shift analyses using a Standard amplitude analysis of the CERN data on pi(-)p->pi(-)pi(+)n on polarized target at 17.2 GeV/c and a more recent analysis of the same data using Spin Mixing Mechanism…

Recent results from the NA48/2 experiment are presented. The $\pi\pi$ scattering lengths $a_0^0$ and $a_0^2$ have been extracted from the cusp in the $M_{00}^2$ distribution of $K^\pm \to \pi^\pm \pi^0 \pi^0$ decays and from the $K^\pm \to…