2018 Impact factor 2.481
Hadrons and Nuclei


Eur. Phys. J. A 14, 469-475 (2002)
DOI: 10.1140/epja/i2002-10031-y

Microscopic three-body force for asymmetric nuclear matter

W. Zuo1, A. Lejeune2, U. Lombardo3 and J.F. Mathiot4

1  Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou, PRC
2  Institut de Physique, B5 Sart-Tilman, B-4000 Liège 1, Belgium
3  Dipartimento di Fisica, 57 Corso Italia, and INFN-LNS, 44 Via Santa Sofia, 95125 Catania, Italy
4  Laboratoire de Physique Corpusculaire, Université Blaise-Pascal, CNRS-IN2P3, 24 Avenue des Landais, F-63177 Aubiere Cedex, France

lombardo@lns.infn.it

(Received: 18 February 2002 / Revised version: 25 April 2002 Communicated by P. Schuck)

Abstract
Brueckner calculations including a microscopic three-body force have been extended to isospin-asymmetric nuclear matter. The effects of the three-body force on the equation of state and on the single-particle properties of nuclear matter are discussed with a view to possible applications in nuclear physics and astrophysics. It is shown that, even in the presence of the three-body force, the empirical parabolic law of the energy per nucleon vs. isospin asymmetry $\beta=(N-Z)/A$ is fulfilled in the whole asymmetry range $0\le\beta\le 1$ up to high densities. The three-body force provides a strong enhancement of the symmetry energy which increases with density in good agreement with the predictions of relativistic approaches. The Lane's assumption that proton and neutron mean fields linearly vary vs. the isospin parameter is violated at high density due to the three-body force, while the momentum dependence of the mean fields turns out to be only weakly affected. Consequently, a linear isospin split of the neutron and proton effective masses is found for both cases with and without the three-body force. The isospin effects on multifragmentation events and collective flows in heavy-ion collisions are briefly discussed along with the conditions for direct URCA processes to occur in the neutron star cooling.

PACS
25.70.-z - Low and intermediate energy heavy-ion reactions.
13.75.Cs - Nucleon-nucleon interactions (including antinucleons, deuterons, etc.).
21.65.+f - Nuclear matter.
24.10.Cn - Many-body theory.

© Società Italiana di Fisica, Springer-Verlag 2002