Hot nuclei -- Landau theory, thermal fluctuations and dissipation
The basic ideas and theoretical methods used in the description of hot nuclei are reviewed. In particular, a macroscopic approach to shape transitions is discussed in the framework of the Landau theory in which the quadrupole shape degrees of freedom play the role of the order parameters. This theory describes the universal features of the nuclear shape evolution with temperature and spin. A unified description of fluctuations in all five quadrupole degrees of freedom is introduced and plays an important role in the calculation of physical observables. A macroscopic approach to the giant dipole resonance (GDR) in hot nuclei is developed. With all parameters fixed by the zero temperature nuclear properties, the theory predicts both the GDR cross-section and angular anisotropy of the {gamma}-rays in very good agreement with recent experiments. The intrinsic shape fluctuations are the main cause for the resonance broadening at higher temperatures, while the orientation fluctuations are responsible for the observed attenuation in the angular anisotropy. Dissipation at finite temperature is discussed in the framework of a Langevin-like equation describing the time-dependent shape fluctuations. Non-adiabatic effects may cause motional narrowing of the resonance.
- Research Organization:
- Yale Univ., New Haven, CT (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-91ER40608
- OSTI ID:
- 5191890
- Report Number(s):
- CONF-9010306-2; YCTP-N-25-90; ON: DE92015008
- Resource Relation:
- Conference: 5. Nishinomiya Yukawa-memorial symposium, Nichinomiya City (Japan), 25-26 Oct 1990
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermal shape fluctuations, Landau theory, and giant dipole resonances in hot rotating nuclei
Orientation fluctuations and the angular distribution of the giant-dipole-resonance. gamma. rays in hot rotating nuclei
Related Subjects
DEFORMED NUCLEI
PHASE TRANSFORMATIONS
CRITICAL TEMPERATURE
CROSS SECTIONS
FLUCTUATIONS
FOKKER-PLANCK EQUATION
GIANT RESONANCE
HEAVY ION FUSION REACTIONS
LANGEVIN EQUATION
MEAN-FIELD THEORY
NUCLEAR STRUCTURE
NUCLEAR TEMPERATURE
DIFFERENTIAL EQUATIONS
EQUATIONS
NUCLEAR REACTIONS
NUCLEI
PARTIAL DIFFERENTIAL EQUATIONS
PHYSICAL PROPERTIES
RESONANCE
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
VARIATIONS
663110* - General & Average Properties of Nuclei & Nuclear Energy Levels- (1992-)