Related papers: Brief report on `Radiative $\phi$ decays with deri…

A phenomenological analysis of the scalar meson f0(980) is performed that relies on the quasi-two body decays D and Ds -> f0(980)P, with P=pi, K. The two-body branching ratios are deduced from experimental data on D or Ds -> pi pi pi, K…

We briefly discuss how the chiral unitary approach in coupled channels and $SU(3)$ symmetry can be used to describe the production of $f_0(500)$, $f_0(980)$ and $a_0(980)$ in the $\chi_{c1} \to \eta \pi^+ \pi^-$ reaction, recently measured…

We investigate the relevance of the meson loops in the $f_0(1710)$ scalar meson decay into one photon and one vector meson, ($\rho$, $\omega$ and $\phi$). In particular we estimate the size of the loops coming from the decay of the…

Data for phi -> gamma (eta-pizero) are analysed using the KK loop model and compared with parameters of a0(980) derived from Crystal Barrel data. The eta-pi mass spectrum agrees closely and the absolute normalisation lies just within…

We study the $D^0 \to \rho^0 \phi$, $\omega \phi$ decays which proceed in a direct mode via internal emission with equal rates. Yet, the experimental branching ratio for the $\rho^0 \phi$ mode is twice as big as that for the $\omega \phi$…

We perform a theoretical study of the $J/\psi \to \omega (\phi) K^* \bar{K} + c.c. \to \omega (\phi) K^0 \pi^+ K^-$ reactions with the assumption that the $f_1(1285)$ is dynamically generated from a single channel $K^* \bar{K} + c.c$…

We address a general problem in the evaluation of triangle loops stemming from the consideration of the range of the interaction involved in some of the vertices, as well as the energy dependence of the width of some unstable particles in…

We discuss the rescattering effects in decays $B\to \pi+K$. The picture we take is very simple: first, B decay into $K*\rho$, then $K*$ and $\rho$ go to kaon and pion by exchanging a pion. We find a up to ten percent CP violation asymmetry…

The measured rate for phi to gamma f0(980) appears to be larger than allowed on rather general grounds. We show that mixing between the f0(980) and a0(980), due to their dynamical interaction with the nearby KKbar thresholds, radically…

In the SND experiment at VEPP-2M $e^+e^-$ collider the $\phi(1020)\to\pi^0\pi^0\gamma$ decay was studied and its branching ratio was measured: $B(\phi\to\pi^0\pi^0\gamma)=(1.221\pm 0.098\pm0.061)\cdot10^{-4}$. It was shown, that…

Using the chiral unitary approach in coupled channels and $SU(3)$ symmetry we describe the production of $f_0(500)$, $f_0(980)$ and $a_0(980)$ in the $\chi_{c1} \to \eta \pi^+ \pi^-$ reaction, recently performed by the BESIII collaboration.…

We propose a model for $D^+ \to \pi^+ \pi^- \pi^+$ decays following experimental results which indicate that the two-pion interaction in the $S$-wave is dominated by the scalar resonances $f_0(600)/\sigma$ and $f_0(980)$. The weak decay…

We employed the chiral unitarity approach to investigate the decay process $\Xi_c^+ \to \Sigma^+K^+K^-$, by considering that the low lying nucleon resonance $\Xi(1/2^-)$ and the low lying scalar meson $f_0(980)$ and $a_0(980)$ that could be…

The two-photon decay widths of scalar mesons \sigma(600), f_0(980) and a_0(980) as well a_0 -> \rho(\omega)\gamma and f_0 -> \rho(\omega)\gamma are calculated in the framework of the local Nambu-Jona-Lasinio model. The contributions of the…

In this write-up, I summarize the analyses on the low-lying scalar mesons I have done recently with my collaborators. I first briefly review the previous analyses on the hadronic processes related to the scalar mesons, which shows that the…

The study of radiative phi decays into scalar mesons, with subsequent decay into pi pi gamma, constitutes an important topic at the electron-positron collider DAPHNE. The interference of the respective amplitude with the one for pi+ pi-…

We calculate the shape of the $\pi\Sigma$ and $\bar K N$ invariant mass distributions in the $\Lambda_b \to J/\psi\, \pi\Sigma$ and $\Lambda_b \to J/\psi \,\bar K N$ decays that are dominated by the $\Lambda(1405)$ resonance. The weak…

The nonleptonic weak decays of charmed mesons into a scalar meson and a pseudoscalar meson are studied. The scalar mesons under consideration are $\sigma$ [or $f_0(600)$], $\kappa$, $f_0(980)$, $a_0(980)$ and $K^*_0(1430)$. A consistent…

We investigate the decay $\phi\to\pi^+\pi^-\pi^0$ in an effective-Lagrangian framework that keeps the dominant $\rho\pi$ mechanism and the direct three-pion term explicitly separated at the amplitude level. The resonant contribution is…

We reexamine radiative corrections to $\pi_{l2}$ and $K_{l2}$ decays. We perform a matching calculation, including vector and axial vector resonances as explicit degrees of freedom in the long distance part. By considering the dependence on…