Related papers: Two-pion decays of mesons and confinement singular…

We present an analysis of the radiative decay $\phi \to \gamma \pi^0 \pi^0$ in a dispersive framework, where the two-pion subsystem undergoes strong final-state interactions that cover the $f_0(500)$ and $f_0(980)$ regions. We employ a…

We study $S$-wave resonance contributions to the $B^0_{(s)}\to J/\psi\pi^+\pi^-$ and $B_s\to\pi^+\pi^-\ell^+\ell^-$ decays in the perturbative QCD (PQCD) framework by introducing two-hadron distribution amplitudes for final states. The…

We propose a phenomenological two component model describing the decay amplitude of the process $D_s^{+} \ra 3 \pi$, whose rate has been found surprisingly large. The first component is a constant background $F_{NR}$, and the second one is…

In this paper, we studied the quasi-two-body $B_c \to D_{(s)} [ \rho(770),\rho(1450),\rho(1700) \to ] \pi \pi$ decays by employing the perturbative QCD (PQCD) factorization approach. The two-pion distribution amplitudes $\Phi_{\pi\pi}$ are…

We propose a phenomenological three component model describing the decay amplitude of the process $D_{s}^{+} \ra 3\pi$. The first component is a constant background, the second one is a Breit-Wigner amplitude associated to a quasi two-body…

In the work presented, the decay of the pionium, that is the \pi^+ \pi^- bound state, into two \pi^0 is studied, the \pi\pi-interaction causing this transition being described by the underlying Weinberg lagrangian. The calculation with such…

In this work, we make a systematical study on the four-body $B_{(s)} \to (\pi\pi)(\pi\pi)$ decays in the perturbative QCD approach, where the $\pi\pi$ invariant mass spectra are dominated by the vector resonance $\rho(770)$ and the scalar…

The dependence of K_{S,L}->\pi^{+}\pi^{-}\gamma decay probabilities on photon polarization is calculated. The phases of terms of amplitude that arise from the pion-pion interaction are obtained by using a simple realistic model of pion-pion…

Decays into three particles are often described in terms of two-body resonances and a non-interacting spectator particle. To go beyond this simplest isobar model, crossed-channel rescattering effects need to be accounted for. We quantify…

We evaluate the two pion decay of the Roper resonance in a model where explicit re-scattering of the two final pions is accounted for by the use of unitarized chiral perturbation theory. Our model does not include an explicit $\epsilon$ or…

We study the radiative $\phi$ decay into $\pi^0 \pi^0 \gamma$ and $\pi^0 \eta \gamma $ taking into account mechanisms in which there are two sequential vector-vector-pseudoscalar or axial-vector--vector--pseudoscalar steps followed by the…

In this paper, we studied the $B_{(s)} \to (D_{(s)},\bar{D}_{(s)}) \rho \to (D_{(s)}, \bar{D}_{(s)})\pi \pi$ decays by employing a framework for the quasi-two-body decays in the perturbative QCD (PQCD) factorization approach. We use the…

$\pi^+\pi^-$ transitions of heavy quarkonia, especially the $ \Upsilon(3S)\to\Upsilon(1S)\pi^+\pi^-$ decay process, are revisited. In the framework of the Chiral Unitary Theory (ChUT), the $S$ wave $\pi\pi$ final state interaction (FSI) is…

We explore the decay of a vector meson to two pseudoscalar mesons on the lattice with $N_f=2$ flavours of sea quark. Although we are working with quark masses that do not allow a physical decay, we show how the transition rate can be…

We study the quasi-two-body decays $B\to D K^*(892) \to D K\pi$ by employing the perturbative QCD approach. The two-meson distribution amplitudes $\Phi_{K\pi}^{\text{$P$-wave}}$ are adopted to describe the final state interactions of the…

Using a relativistic constituent quark model based on point form of relativistic quantum mechanics with given set of degrees of freedom we investigate electroweak decays of the pion and rho mesons. All free parameters of quark model (the…

Deconfinement and chiral symmetry restoration are explored in a confining, renormalisable, Dyson-Schwinger equation model of two-flavour QCD. An order parameter for deconfinement is introduced and used to establish that, in the chiral…

We consider the $B \to \pi \pi $ and $B \to \pi \rho, \pi \omega $ decays alongside each other, taking into account the contributions from all individual penguin amplitudes generated by the internal $t$, $c$, and $u$ quarks. We argue that…

The decay widths of four-body double-pion decays $\ds\to pn \pi^0\pi^0$, $\ds\to pn \pi^+\pi^-$, and iso-scalar parts of $\ds\to pp \pi^0\pi^-$ and $\ds\to nn \pi^+\pi^0$ are explicitly calculated with the help of the $d^*$ wave function…

It is shown that the basic shape of dipion mass distributions in the two-pion transitions of both charmonia and bottomonia states are explained by an unified mechanism based on the contribution of the $\pi\pi$, $K\overline{K}$ and…