2005/10/25 by V. A. Sadovnikova, Sadovnikova, V. A.
Physics and Astronomy · #FOS: Physical sciences #Nuclear Theory (nucl-th) #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #Quantum, superfluid, helium dynamics #nucl-th
paper · pdf · doi:10.48550/arxiv.nucl-th/0510076
20 pages, 10 figures
arxiv created 2005/10/25 · openalex publication_date 2005/10/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper we consider instability of nuclear matter which takes place when the frequencies of the collective excitations turn to zero. We investigate collective excitations with pion quantum numbers Jπ=0-. We study the dependence of zero-frequency solutions of the pion dispersion equation on the value of the spin-isospin quasiparticle interaction G'. The solutions of the pion dispersion equation describe the different types of the excitations in the matter, ωi(k). At the critical density ρ=ρc one of solutions of the definite type turns to zero: ωi0(kc)=0. When ρ>ρc, the excitations ωi0(k) become amplified. It is shown that there is such a "transitional" value of G'=G'tr that for G'G'tr they pertain to the type ωc. The solutions of the type ωsd correspond to instability to small density fluctuations of the nuclear matter at G'≤ -1. On the other hand, ωc is responsible for the "pion condensation" at G'≈ 2. For the stable nuclear matter the branches of solutions ωsd(k) and ωc(k) are located on the unphysical sheets of the complex plane of frequency.