High-lying single-particle modes, chaos, correlational entropy, and doubling phase transition

Abstract

Highly-excited single-particle states in nuclei are coupled with the excitations of a more complex character, first of all with collective phonon-like modes of the core. In the framework of the quasiparticle-phonon model we consider the structure of resulting complex configurations using the $1k_{17/2}$ orbital in ${}^{209}$Pb as an example. Although, on the level of one- and two-phonon admixtures, the fully chaotic GOE regime is not reached, the eigenstates of the model carry significant degree of complexity that can be quantified with the aid of correlational invariant entropy. With artificially enhanced particle-core coupling, the system undergoes the doubling phase transition with the quasiparticle strength concentrated in two repelling peaks. This phase transition is clearly detected by correlational entropy.

8 pages, 6 figures

References in corpus (7)

• Statistical Theory of Finite Fermi-Systems Based on the Structure of Chaotic Eigenstates
• Chaos {\sl vs} Thermalization in the Nuclear Shell Model
• Nuclear Structure, Random Interactions and Mesoscopic Physics
• Invariant Correlation Entropy and Complexity of Quantum States
• Structure of wavefunctions in (1+2)-body random matrix ensembles
• Invariant correlational entropy as a signature of quantum phase transitions in nuclei
• Population of isomers in decay of the giant dipole resonance

Cited by in corpus (6)

• Quantum Chaos and Thermalization in Isolated Systems of Interacting Particles
• Thermodynamics of pairing in mesoscopic systems
• Nuclear Schiff moment in nuclei with soft octupole and quadrupole vibrations
• Temperature dependence of nuclear spin-isospin response and beta decay in hot astrophysical environments
• Nuclear Structure and the Search for Collective Enhancement of P,T-Violation
• Spreading widths of giant monopole resonance in the lead region: Random matrix approach