Related papers: A Calculation of the Sigma Meson Mass in Nuclear M…
We calculate the physical mass and the width of the sigma meson by considering that it couples in vacuum to two virtual pions. The mass is calculated by using the spectral function, and we find that it is about 600MeV. In addition, we…
The propagation of sigma meson in nuclear matter is studied in the Walecka model, assuming that the sigma couples to a pair of nucleon-antinucleon states and to particle-hole states, including the in medium effect of sigma-omega mixing. We…
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…
The propagation of the scalar ($\sigma$) and vector ($\omega$) mesons in nuclear matter is studied in detail using the Walecka model over a wide range of densities and including the effects of a finite $\sigma$ width through the inclusion…
We obtain the width of the $\omega$ meson in dense nuclear matter by taking into account (i) the free decay of the $\omega$ into three pions, which is dominated by $\rho \pi$ mode, (ii) the processes induced by a vector-baryon interaction…
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…
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…
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 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…
We study the modification of hadron masses due to the vacuum polarization using the chiral sigma model, which is extended to generate the $\omega$ meson mass by the sigma condensation in the vacuum in the same way as the nucleon mass. The…
We calculate the spectral function of the omega meson in nuclear matter at zero temperature by means of the low-density theorem. The omega N forward scattering amplitude is calculated within a unitary coupled-channel effective Lagrangian…
A variety of strong and electroweak interaction properties of the pion and the light scalar sigma meson are computed in a relativistic quark model. Under the assumption that the resulting coupling of these mesons to the constituent quarks…
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…
We analyze Nf=2 nucleon mass data with respect to their dependence on the pion mass down to mpi = 157 MeV and compare it with predictions from covariant baryon chiral perturbation theory (BChPT). A novel feature of our approach is that we…
We study two coupling constants reported as predictions of the sigma model. We obtain an spectral distribution, in terms of the \sigma meson regularized self- energy in one loop order, which is consistently with the Breit-Wigner…
We calculate the effective mass m_\omega^* of the \omega-meson in nuclear medium by the \sigma-\omega model with a vector field self-interaction (VFSI). We found that the direct and the indirect effects of the VFSI almost cancel each other…
We present theoretical results for (gamma,pi0 pi0) and (gamma,pi+- pi0) production on nucleons and nuclei in the kinematical region where the scalar isoscalar pi pi amplitude is influenced by the sigma pole. The final state interaction of…
The propagation of the scalar (\sigma and \delta) and vector (\omega and \rho) mesons in an iso-asymmetric nuclear matter is studied in detail, using the Walecka model. We calculate the invariant masses and spectral functions of the mesons,…
We present theoretical results for $(\gamma, \pi^0 \pi^0)$ production on nucleons and nuclei in the kinematical region where the scalar isoscalar $\pi \pi$ amplitude is influenced by the $\sigma$ pole. The final state interaction of the…
The influence of the in-medium mesons on the effective nucleon mass and in turn on the equation of state of hot/dense nuclear matter is discussed in the Walecka model. Due to the self-consistent treatment of couplings between nucleons and…