Nuclear Matter Studies with Density-dependent Meson-Nucleon Coupling Constants

Abstract

Due to the internal structure of the nucleon, we should expect, in general, that the effective meson nucleon parameters may change in nuclear medium. We study such changes by using a chiral confining model of the nucleon. We use density-dependent masses for all mesons except the pion. Within a Dirac-Brueckner analysis, based on the relativistic covariant structure of the NN amplitude, we show that the effect of such a density dependence in the NN interaction on the saturation properties of nuclear matter, while not large, is quite significant. Due to the density dependence of the $g_{\sigma NN}$, as predicted by the chiral confining model, we find, in particular, a looping behavior of the binding energy at saturation as a function of the saturation density. A simple model is described, which exhibits looping and which is shown to be mainly caused by the presence of a peak in the density dependence of the medium modified $\sigma N$ coupling constant at low density. The effect of density dependence of the coupling constants and the meson masses tends to improve the results for $E/A$ and density of nuclear matter at saturation. From the present study we see that the relationship between binding energy and saturation density may not be as universal as found in nonrelativistic studies and that more model dependence is exhibited once medium modifications of the basic nuclear interactions are considered.

Acknowledgements have been modified. 34 pages, revtex, uuencoded gz-compressed tar file

Cited by in corpus (9)

• Nucleon and hadron structure changes in the nuclear medium and impact on observables
• The Stability of Nuclear Matter in the Nambu-Jona-Lasinio Model
• Quark-meson coupling model with constituent quarks: Exchange and pionic effects
• Density dependence of meson - nucleon vertices in nuclear matter
• A self-consistent approach to the Wigner-Seitz treatment of soliton matter
• The role of tensor force in nuclear matter saturation
• rho -> pi pi decay in nuclear medium
• pi^0 -> gamma gamma*, omega -> pi^0 gamma*, and rho -> pi gamma* decays in nuclear medium
• QCD chiral condensate and pseudoscalar-meson properties in the nuclear medium at finite temperature