Theory for Quartet Condensation in Fermi Systems with Applications to Nuclei and Nuclear Matter

17th International Conference on Recent Progress in Many-Body Theories

Schuck, P.^1,2,3 ; Funaki, Y.^4 ; Horiuchi, H.^5 ; Röpke, G.^6 ; Tohsaki, A.^5 ; Yamada, T.^7

Institut de Physique Nucléaire, CNRS, UMR8608, F-91406 Orsay, France^1

Université Paris-Sud, F-91505 Orsay, France^2

Laboratoire de Physique et de Modélisation des Milieux Condensés, CNRS, Université Joseph Fourier, 25 Av. des Martyrs, F-38042 Grenoble Cedex 9, France^3

Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, 351-0198, Japan^4

Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Osaka 567-0047, Japan^5

Institut für Physik, University of Rostock, Universitätsplatz 1, 18051 Rostock, Germany^6

Laboratory of Physics, Kanto Gakuin University, Yokohama 236-8501, Japan^7

关键词: Critical temperatures;    Gross-Pitaevski equation;    Mott transitions;    Nuclear matters;    Order parameter;    Strong coupling;    Weak couplings;    Zero temperatures;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/529/1/012014/pdf
DOI  :  10.1088/1742-6596/529/1/012014

来源: IOP

【 摘 要 】

The theory of quartet condensation is further developed. The onset of quartet- ting in homogeneous fermionic matter is studied with the help of an in-medium modified four fermion equation. It is found that at very low density quartetting wins over pairing. At zero temperature, in analogy to pairing, a set of equations for the quartet order parameter is given. Contrary to pairing, quartetting only exists for strong coupling and breaks down for weak coupling. Reasons for this finding are detailed. In an application to nuclear matter, the critical temperature for α particle condensation can reach values up to around 8 MeV. The disappearance of α-particles with increasing density, i.e. the Mott transition, is investigated. In finite nuclei the Hoyle state, that is the 02+of12C is identified as an 'α-particle condensate' state. It is conjectured that such states also exist in heavier na-nuclei, like16O,20Ne, etc. The sixth 0+state in16O is proposed as an analogue to the Hoyle state. The Gross-Pitaevski equation is employed to make an estimate of the maximum number of a particles a condensate state can contain. Possible quartet condensation in other systems is discussed briefly.