相关论文: Nuclear medium effects on the sigma mass and width
The sigma meson mass and width are studied at finite baryonic density in the framework of a chiral unitary approach which successfully reproduces the meson meson phase shifts and generates the f0 and sigma resonances in vacuum.
The $\pi\pi$ scattering amplitude in the $\sigma$-channel is studied at finite baryonic density in the framework of a chiral unitary approach which successfully reproduces the meson meson phase shifts and generates the $f_0$ and $\sigma$…
We present a study of the $\pi\pi$ scattering amplitude in the $\sigma$ and $\rho$ channels at finite temperature and nuclear density within a chiral unitary framework. Meson resonances are dynamically generated in our approach, which…
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…
The meson meson interaction in the scalar sector in the presence of a nuclear medium is studied with particular attention to the change of the properties of the f0(980) and a0(980) resonances. By using a chiral unitary approach which…
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…
It should be a typical subject in this workshop to explore possible change of hadron properties in association with that of QCD vacuum due to an environmental change. In this report, we first summarize what hadrons are expected to show such…
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 role of light scalar meson `$f_0 (600)$' is investigated in nuclear matter in an Effective chiral model in the mean-field approach. For the purpose, we scan the properties of the matter at various saturation densities imposing…
We investigate the in-medium masses of a $\bar{D} (0^-)$ meson and a $\bar{D}_0^* (0^+)$ meson and spectral functions for $\bar{D}$ and $\bar{D}_0^*$ meson channels in nuclear matter. These mesons are introduced as chiral partner in the…
We first review the recent accumulating evidences of the existence of a scalar-isoscalar meson with the mass 500 to 800 MeV which may be identified with the sigma meson as the quantum fluctuation of the amplitude of the chiral order…
A theoretical analysis of the $(\pi^-,\gamma\gamma)$ reaction in nuclei is made in order to find the viability of this reaction to test modifications of the $\sigma$ meson mass in nuclear matter. The $\pi\pi$ correlation in the…
Recent studies of the $\Lambda(1520)$ resonance within chiral unitary theory with coupled channels find the resonance as a dynamically generated state from the interaction of the decuplet of baryons and the octet of mesons, essentially a…
We show 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 pions…
We study the structure and formation of the $\phi$ mesic nuclei to investigate the in-medium modification of the $\phi$-meson spectral function at finite density. We consider (${\bar p},\phi$), ($\gamma,p$) and ($\pi^-,n$) reactions to…
Results for the $\pi + N \to \Lambda, \Sigma + K$ reactions in nuclear matter of Ref. nucl-th/0004011 are presented. To evaluate the in-medium modification of the reaction amplitude as a function of the baryonic density we introduce…
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…
The sigma-meson, which is at best a broad resonance in the vacuum, may suffer a substantial red-shift and appear as a soft and narrow collective mode at finite temperature and baryon densities. The physics behind this softening phenomena…
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…
It has been argued that the iso-scalar and iso-vector mesons play significant roles in nuclear matter and neutron star structures. We improve the extended linear sigma model with baryons, proposed in our previous work, by introducing the…