Related papers: Matter-induced omega -> pi pi decay
We study the changes in the partial decay widths of excited charmonium states into $D \bar{D}$, when the D meson mass decreases in nuclear matter, taking the internal structure of the hadrons into account. Calculations within the 3P0 model…
Some atomic decays of elementary particles with pionium ($\pi^+\pi^-$-dimesoatom) in the final state are considered. Only for K-meson atomic decays are the corresponding branching ratios big enough to make their experimental study…
We show that $\phi$ radiative decays into scalar mesons [$f_0$(975), $a_0$(980)$\equiv S$] can provide important clues on the internal structures of these mesons. Radiative decay widths vary widely: $B.R.=10^{-4}-10^{-6}$ depending on the…
We study polarization variables in the photoproduction of omega-mesons with subsequent omega to gamma pi^0 decay. Single and double polarization observables are calculated as a function of different final-state angles. Reaction models…
We study nuclear matter and finite nuclei with a chiral Lagrangian which generalizes the linear $\sigma$ model and also accounts for the QCD trace anomaly by means of terms which involve the $\sigma$ and $\vmg{\pi}$ fields as well as the…
The neutrinoless double-beta ($0\nu\beta\beta$) decay is a unique process to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass $\langle m\rangle_{ee}$. We put forward…
We calculate the effective mass of the $\omega$ meson in nuclear matter in a relativistic random-phase approximation to the Walecka model. The dressing of the meson propagator is driven by its coupling to particle-hole pairs and…
We calculate dispersion relations and propagators for the $\sigma$, $\omega$, $\pi$, $\rho$, $\delta$, $\eta$ and $a_1$ mesons in relativistic, dense, hot, symmetric nuclear matter. In addition to the usual mixing of the $\sigma-\omega$…
The pi-mesonic decay of the hypertriton is calculated based on a hypertriton wavefunction and 3N scattering states, which are rigorous solutions of 3-body Faddeev equations using realistic NN and hyperon-nucleon interactions. The total…
We investigate the in-medium properties of the $\phi$ meson with finite momentum, going beyond the commonly studied case at rest. In a nuclear medium, Lorentz invariance is broken, leading to distinct longitudinal and transverse…
We study strong decays of nonstrange baryons by making use of the algebraic approach to hadron structure. Within this framework we derive closed expressions for decay widths in an elementary-meson emission model and use these to analyze the…
We calculate the cross section of the inverse beta decay process, $\nu_e+n\to p+e$, in a background magnetic field which is much smaller than $m_p^2/e$. Using exact solutions of the Dirac equation in a constant magnetic field, we find the…
The pi+pi- atom decays -in the ground state - predominantly into two neutral pions. We present a general expression for the corresponding decay width in the framework of QCD (including photons). It contains all terms at leading and…
The possibility of extending the linear sigma-omega model by introducing a sigma-omega coupling phenomenologically is explored. It is shown that, in contrast to the usual Walecka model, not only the effective nucleon mass M* but also the…
The hadronic decays eta -> pi pi pi, eta-prime -> pi pi pi and eta-prime -> eta pi pi are investigated within a U(3) chiral unitary approach. Final state interactions are included by deriving the effective s-wave potentials for meson meson…
Experimental searches for modifications of vector mesons in the nuclear medium are reviewed. Data on $\rho,\omega$ and $\Phi$ mesons are presented. The results have been obtained in elementary reactions with proton and photon beams as well…
Radiative decays $\pi^0({\pi^0}')\to\gamma+\gamma$, ${\pi^0}'\to\rho^0(\omega)+\gamma$, ${\rho^0}'(\omega')\to\pi^0+\gamma$, and ${\rho^0}'(\omega')\to{\pi^0}'+\gamma$ are considered in the framework of the non-local SU(2)$\times$SU(2) NJL…
The $\omega$-, $\rho$- and $\phi$-resonance production and their dileptonic decay in $\pi^- A$ reactions at 1.1 - 1.7 GeV/c are calculated within the intranuclear cascade (INC) approach. The invariant mass distribution of the dilepton pair…
Using the fact that the contribution of the states with isospin I=0 in the difference of the amplitudes of the processes \gamma \gamma->\pi^+\pi^- and \gamma\gamma->\pi^0\pi^0 is very small, we have analyzed the dispersion sum rules for the…
We discuss the possibility to study the in-medium changes of the properties of the omega meson in reactions on ordinary nuclei with elementary electromagnetic probes. We present a tree-level calculation of the elementary gamma p -> omega p…