F. Matera et Vy. Denisov, COLLECTIVE MODES AND RESPONSE FUNCTIONS OF RELATIVISTIC ASYMMETRIC NUCLEAR-MATTER, Physical review. C. Nuclear physics, 49(5), 1994, pp. 2816-2819
Response functions and collective modes for asymmetric nuclear matter
(N > Z) are studied by means of a relativistic kinetic equation. Nucle
ar matter is described by means of a field theory Of nucleons coupled
to neutral, scalar (sigma), and vector (omega) mesons and to charged v
ector mesons (rho). The contribution of the exchange terms to the nucl
eon-nucleon interaction is also taken into account. Because of the exc
hange terms, the kinetic equation presents solutions which correspond
to oscillations of the spin density. Finally the effects of an excess
of neutrons on the response functions and on the collective modes are
investigated. It is found that a collective oscillation present in sym
metric nuclear matter disappears even for a small asymmetry (approxima
tely 5%).