Related papers: Annihilation into Channels with Strangeness and th…
The role of two step mechanisms in the OZI rule violation in NNbar annihilation at low energies is reviewed. The full calculation of two-meson doorway mechanisms shows that the off-mass-shell contributions are important. Moreover, for the…
The phi pi+ pi- production in p pbar annihilation at rest is strongly enhanced by a two step mechanism with intermediate K Kbar pi pi states. The relative yield of the phi production due to the resonant final state interaction decreases…
We evaluate three meson doorway mechanisms for nucleon-antinucleon annihilation at rest for the first time. Detailed results are presented for the final state phi pi0 originating from the 3S1 initial state and for the phi rho channel…
A large apparent violation of the OZI rule has recently been found in many channels in pbar-p annihilation LEAR. An interpretation of these data in terms of the "shake-out" and "rearrangement" of an intrinsic sbar-s component of the nucleon…
The results of a measurement of the ratio R = Y(phi pi+ pi-) / Y(omega pi+ pi-) for antiproton annihilation at rest in a gaseous and in a liquid hydrogen target are presented. It was found that the value of this ratio increases with the…
We study antiproton-proton annihilation at rest into $\pi\phi$ and $\gamma\phi$. Rescattering by $\overline{K^*}K+K^*\overline{K}$ and $\rho^{+}\rho^{-}$ for $\overline{p}p\rightarrow\pi\phi$ states is sizable, of order $(0.90\, {\rm…
The question is raised if a large violation of the OZI rule, recently observed in many channels in $N \bar N$ annihilation at rest, can be explained in the framework of the Skyrme model.
We employ an effective Lagrangian approach to investigate double $\phi$ production in the $\bar{p}p$ reaction near the threshold and describe a notable violation of the Okubo-Zweig-Iizuka (OZI) rule in this reaction process through hadronic…
Violations of the Okubo-Zweig-Iizuka (OZI) rule in $s\bar s <-> n\bar n = 1/2 (u\bar u + d\bar d)$ mixing and $\phi$ production from nucleon-antinucleon annihilation are reviewed. Possible explanations are examined. We conclude that the…
We investigate double $\phi$ production in $\bar{p}p$ reactions near threshold using an effective Lagrangian approach, highlighting a significant OZI rule violation through hadronic processes. Our model includes $t$- and $u$-channel…
Using the vector meson dominance model we get predictions for the Cabibbo-favored $\tom$ and $\tphi$ decays. We show how the measurements of these two decays can provide information on the nature of the violation of the OZI rule.
We investigate OZI rule violation in omega and phi-meson photoproduction off nucleons. Data on the total cross sections indicate a large phi/omega ratio of about 0.8 at the maximal available photon energy that is in good agreement with…
We investigate the reactions p n -> d omega and p n -> d phi close to threshold and at higher energies. Near threshold we calculate the S-wave amplitudes within the framework of the two-step model which is described by a triangle graph with…
Radiative decays of the $\phi$ meson have been studied using a data sample of about 19 million $\phi$ decays collected by the CMD-2 detector at VEPP-2M collider in Novosibirsk. From selected $e^+e^-\to\pi^{0}\pi^{0}\gamma$ and…
The s-channel annihilation of proton and antiproton into a neutral pion and a real or virtual photon followed by lepton pair emission is studied. Such mechanism is expected to play a role at moderate values of the total energy $\sqrt{s}$,…
The experimental observation indicates that the branching ratio of $\psi'\to \rho\pi$ is very small while the $\rho-\pi$ channel is a main one in $J/\psi$ decays. To understand the puzzle, various interpretations have been proposed.…
The aim of this work is to identify the mechanisms responsible for very large rates and other peculiarities observed in low-energy positron annihilation on molecules. The two mechanisms considered are: (i) Direct annihilation of the…
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 have studied the invariant mass distributions of the \pi\pi and K \bar{K} systems for invariant masses up to 1.2 GeV from the J/\Psi \to \phi \pi\pi(K\bar{K}) decays. The approach exploits the connection between these processes and the…
It is shown, that specific properties of the instanton induced interaction between quarks leads to the anomalous violation of the OZI-rule in the $N\bar N\to \Phi\Phi$, $N\bar N\to \Phi\gamma$ reactions. In the framework of instanton model…