Related papers: Why the f(0)(980) is mostly ssbar
We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass differences and electromagnetism.…
The potentialities of the production of the $a_0$ and $f_0$ mesons in the $\phi$ radiative decays are considered based on a new two-channel analysis of the $\pi\pi$ scattering in a energy region near 1 GeV. We predict $BR(\phi\to\gamma…
We investigate the $D^0-\bar D^0$ mixing through the doubly Cabibbo suppressed (DCS) channel $D^0\to f_0(980)K^{*0}$ and its charge conjugate channel, in which the $K^{*0}$ meson is reconstructed in both $K^+\pi^-$ and $K_S\pi^0$ final…
We report the first measurement of the branching fraction f00 for Upsilon(4S) --> B0B0bar. The data sample consists of 81.7 fb^-1 collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy e^+e^- storage…
The structure of the light scalar mesons is elucidated by the investigation of the S-matrix poles and the q-qbar spectral density in a coupled channel model that includes pi-pi, K-Kbar and q-qbar channels. It is shown that the dynamical…
Based on the main assumption that the $a_0(980)$ and $D^\ast_{sJ}(2317)$ belong to the $1 ^3P_0$ $q\bar{q}$ multiplet, in the framework of Regge phenomenology and meson-meson mixing, it is suggested that the $a_0(980)$, $K^\ast_0(1052)$,…
We study the interactions between the f_0(980) and a_0(980) scalar resonances and the lightest pseudoscalar mesons. We first obtain the elementary interaction amplitudes, or interacting kernels, without including any ad hoc free parameter.…
We present a two-flavour linear sigma model with global chiral symmetry and vector and axial-vector mesons. We calculate pion-pion scattering lengths and the decay widths of scalar, vector, and axial-vector mesons. It is demonstrated that…
The scalar meson exchange in $\phi\to P^0 P^0\gamma$ decays is discussed in a chiral invariant framework where the scalar meson poles are incorporated explicitly. $\phi\to\pi^0\pi^0\gamma$ and $\phi\to\pi^0\eta\gamma$ are in agreement with…
The $K^+$ and $K^0$ meson mass difference induces the mixing of the $a^0_0(980)$ and $f_0(980)$ resonances, the amplitude of which, between the $K^+K^-$ and $K^0\bar K^0$ thresholds, is large in magnitude, of the order of $…
Using 7.33~fb$^{-1}$ of $e^{+}e^{-}$ collision data collected by the BESIII detector at center-of-mass energies in the range of $\sqrt{s}=4.128 - 4.226$~GeV, we search for the rare decays $D_{s}^+\to h^+(h^{0})e^{+}e^{-}$, where $h$…
We report on the evidence for the decays B0 -> Ds+ pi- and B0 -> Ds- K+ and the results of a search for the decays B0 -> Ds*+ pi- and B0 -> Ds*-K+ from a sample of 84 million Upsilon(4S) decays into B meson pairs collected with the BABAR…
We measure the $D^0 - {\bar{D}}^0$ mixing parameters using a time-dependent amplitude analysis of the decay $D^0\to\pi^+\pi^-\pi^0$. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\Upsilon(4S)$…
We study the decay $\phi\to\gamma K^+K^-$ taking into account the scalar mesons production $\phi\to\gamma(f_0+a_0) \to\gamma K^+K^-$ and the final state radiation. We note that the relative sign between the final state radiation amplitude…
We present lattice results for the form factors relevant in the K -> pion and D -> pion semileptonic decays, obtained from simulations with two flavors of dynamical twisted-mass fermions and pion masses as light as 260 MeV. For K -> pion…
The crucial points of physics of light scalar mesons are discussed. The special attention is given to the chiral shielding of lightest scalar mesons and the production of the well established light scalar mesons in the \phi radiative…
The unusual properties of the X(3872) have led to speculation that it is a weakly bound state of mesons, chiefly $D^0\bar D^{0*}$. Tests of this hypothesis are investigated and it is proposed that measuring the $3\pi J/\psi$, $\gamma…
We consider a possible interpretation of the new charm-strange meson Ds0*(2317) as a hadronic molecule - a bound state of D and K mesons. Using an effective Lagrangian approach we calculate the strong Ds0* to Ds pi0 and radiative Ds0* to…
We discuss a new type of L=0 positive-parity dibaryons, pion-B-B', where the dominant binding mechanism is provided by resonating p-wave pion-baryon interactions. Recent calculations of such pion assisted dibaryons are reviewed with special…
A search for mixing in the neutral D meson system has been performed using semileptonic D^0 \to K^(*)- e^+ nu decays. Neutral D mesons from D^*+ \to D^0 pi+ decays are used; the flavor at production is tagged by the charge of the slow pion.…