相关论文: The width of the $\omega$ meson in dense matter
We evaluate the width of the $\omega$ meson in nuclear matter. We consider the free decay mode of the $\omega$ into three pions, which is dominated by $\rho \pi$ decay, and replace the $\rho$ and $\pi$ propagators by their medium modified…
The mass shift, width broadening, and spectral density for the $\omega$ meson in a heat bath of nucleons and pions is calculated using a general formula which relates the self-energy to the forward scattering amplitude. We use experimental…
We calculate the width for the omega -> pi pi decay in nuclear matter in a hadronic model including mesons, nucleons and Delta isobars. We find a substantial width of the longitudinally polarized omega modes, reaching ~100MeV for mesons…
The mass shift, width broadening, and spectral density for the $\rho$ and $\omega$ mesons in a heat bath of nucleons and pions are calculated using a general formula which relates the self-energy to the real and imaginary parts of the…
The properties of vector mesons in nuclear matter are discussed. Results for the momentum dependence of the $\rho$-meson self energy in matter due to $\rho N$ interactions are presented, and consequences for the production rate of $e^+e^-$…
The width of the $\omega$ meson in cold nuclear matter is computed in a hadronic many-body approach, focusing on a detailed treatment of the medium modifications of intermediate $\pi\rho$ states. The $\pi$ and $\rho$ propagators are dressed…
The decay width of the $\omega$ meson at finite temperature is calculated using the Gell-Mann Sharp Wagner model of $\rho$ pole dominance. Effective masses of the $\rho$ and $\omega$ are determined within the framework of real-time…
The mass and decay width of the $\phi$ meson in cold nuclear matter are computed in an effective Lagrangian approach, with the medium dependence of these properties obtained by evaluating kaon-antikaon loop contributions to the $\phi$…
We calculate the width for the omega -> pi pi decay in nuclear medium. Chiral dynamics and low-density approximation are used. At densities around twice the nuclear saturation density we estimate the partial width for the decay of the…
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…
The $\phi$ meson spectrum, which in vacuum is dominated by its coupling to the $\bar{K} K$ system, is modified in nuclear matter. Following a model based on chiral SU(3) dynamics we calculate the $\phi$ meson selfenergy in nuclear matter…
The mass and decay width of the $\phi$ meson in cold nuclear matter are computed in an effective Lagrangian approach. The medium dependence of these properties are obtained by evaluating kaon-antikaon loop contributions to the $\phi$…
We calculate the mass and width of the sigma meson in nuclear medium by considering that it couples to two virtual pions and to a pair of nucleon-antinucleon states and to particle-hole states. The mass is calculated by using the spectral…
Mass shifts $\Delta m$ of particles in nuclear matter relative to their vacuum values are considered. A general formula relating $\Delta m(E)$ ($E$ is the particle energy) to the real part of the forward particle-nucleon scattering…
We investigate the role of the softening of the scalar-isoscalar (sigma) meson in the $\eta\rightarrow\pi^+\pi^-\pi^0$ and $3\pi^0$ decay widths in the symmetric nuclear medium using a linear sigma model. Our calculation shows that these…
The photo production of $\omega$ mesons on the nuclei C, Ca, Nb and Pb has been measured using the Crystal Barrel/TAPS detector at the ELSA tagged photon facility in Bonn. The dependence of the $\omega$ meson cross section on the nuclear…
We discuss an asymmetry of the decay $\omega->e^+e^-$ in nuclear matter with respect to the electron and positron energies. This asymmetry is sensitive to the properties of the $\omega$ meson self-energy and, in particular, it has a…
We have studied the decay of the \phi meson in nuclear matter by taking into account the renormalization of the K and \bar{K} mesons in the medium. We separate the contribution of the total width into different reaction channels, K\bar{K}…
The vacuum spectrum of the $\phi$-meson is characterized by its decay into $K{\bar K} $. Modifications of the $K {\bar K}$-loops in baryonic matter change this spectrum. We calculate these in-medium modifications taking both s- and p-wave…
We calculate the momentum dependence of the $\rho$-meson selfenergy based on the dispersion relation for the $\rho N$ scattering amplitude $f(\omega$) at low nuclear density. The imaginary part of $f(\omega)$ is determined from the optical…