Spin distribution of nuclear levels using the static path approximation with the random-phase approximation

Journal Article · Sun Apr 15 00:00:00 EDT 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.75.044304· OSTI ID:20995197

Kaneko, K ^[1]; Schiller, A ^[2]

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1. Department of Physics, Kyushu Sangyo University, Fukuoka 813-8503 (Japan)
2. National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

We present a thermal and quantum-mechanical treatment of nuclear rotation using the formalism of the static path approximation plus the random-phase approximation. Naive perturbation theory fails because of the presence of zero-frequency modes resulting from dynamical symmetry breaking. Such modes lead to infrared divergences. We show that composite zero-frequency excitations are properly treated within the collective coordinate method. The resulting perturbation theory is free from infrared divergences. Without the assumption of individual random spin vectors, we derive microscopically the spin distribution of the level density. The moment of inertia is thereby related to the spin-cutoff parameter in the usual way. Explicit calculations are performed for {sup 56}Fe; various thermal properties are discussed. In particular, we demonstrate that the increase of the moment of inertia with increasing temperature is correlated with the suppression of pairing correlations.

• OSTI ID: 20995197
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 75, Issue 4; Other Information: DOI: 10.1103/PhysRevC.75.044304; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COLLECTIVE MODEL
DEFORMED NUCLEI
DISTRIBUTION
ENERGY LEVELS
ENERGY-LEVEL DENSITY
EXCITATION
INFRARED DIVERGENCES
IRON 56
MASS NUMBER
MOMENT OF INERTIA
PERTURBATION THEORY
QUANTUM MECHANICS
RANDOM PHASE APPROXIMATION
SPIN
SYMMETRY BREAKING
THERMODYNAMIC PROPERTIES
VECTORS