The European Physical Journal A

, 52:362

Scalar quanta in Fermi liquids: Zero sounds, instabilities, Bose condensation, and a metastable state in dilute nuclear matter

Regular Article - Theoretical Physics

DOI: 10.1140/epja/i2016-16362-0

Cite this article as:
Kolomeitsev, E.E. & Voskresensky, D.N. Eur. Phys. J. A (2016) 52: 362. doi:10.1140/epja/i2016-16362-0


The spectrum of bosonic scalar-mode excitations in a normal Fermi liquid with local scalar interaction is investigated for various values and momentum dependence of the scalar Landau parameter \(f_{0}\) in the particle-hole channel. For \(f_{0} > 0\) the conditions are found when the phase velocity on the spectrum of zero sound acquires a minimum at non-zero momentum. For \(-1 < f_{0} < 0\) there are only damped excitations, and for \(f_{0} < -1\) the spectrum becomes unstable against the growth of scalar-mode excitations. An effective Lagrangian for the scalar excitation modes is derived after performing a bosonization procedure. We demonstrate that the instability may be tamed by the formation of a static Bose condensate of the scalar modes. The condensation may occur in a homogeneous or inhomogeneous state relying on the momentum dependence of the scalar Landau parameter. We show that in the isospin-symmetric nuclear matter there may appear a metastable state at subsaturation nuclear density owing to the condensate. Then we consider a possibility of the condensation of the zero-sound-like excitations in a state with a non-zero momentum in Fermi liquids moving with overcritical velocities, provided an appropriate momentum dependence of the Landau parameter \(f_{0}(k) > 0\). We also argue that in peripheral heavy-ion collisions the Pomeranchuk instability may occur already for \(f_{0} > -1\).

Copyright information

© SIF, Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Matej Bel UniversityBanska BystricaSlovakia
  2. 2.National Research Nuclear University (MEPhI)MoscowRussia

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