Experimental First Order Pairing Phase Transition in Atomic Nuclei

11th International Spring Seminar on Nuclear Physics: Shell Model and Nuclear Structure – achievements of the past two decades

Moretto, L.G.^1 ; Larsen, A.C.^2 ; Giacoppo, F.^2 ; Guttormsen, M.^2 ; Siem, S.^2

Lawrence Berkeley National Laboratory, University of California, Berkeley

CA

94720, United States^1

Department of Physics, University of Oslo, Oslo

N-0316, Norway^2

关键词: Atomic nuclei;    Critical temperatures;    First order;    Gap parameter;    Mass difference;    Nuclear level densities;    Quasi particles;    Rotational state;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/580/1/012048/pdf
DOI  :  10.1088/1742-6596/580/1/012048

来源: IOP

【 摘 要 】

The natural log of experimental nuclear level densities at low energy is linear with energy. This can be interpreted in terms of a nearly 1st order phase transition from a superfluid to an ideal gas of quasi particles. The transition temperature coincides with the BCS critical temperature and yields gap parameters in good agreement with the values extracted from even- odd mass differences from rotational states. This converging evidence supports the relevance of the BCS theory to atomic nuclei.