Fossez K, Rotureau J, Michel N, Płoszajczak M
NSCL/FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
JINPA, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Phys Rev Lett. 2017 Jul 21;119(3):032501. doi: 10.1103/PhysRevLett.119.032501.
The search for a resonant four-neutron system has been revived thanks to the recent experimental hints reported in [1]. The existence of such a system would deeply impact our understanding of nuclear matter and requires a critical investigation. In this work, we study the existence of a four-neutron resonance in the quasistationary formalism using ab initio techniques with various two-body chiral interactions. We employ no-core Gamow shell model and density matrix renormalization group method, both supplemented by the use of natural orbitals and a new identification technique for broad resonances. We demonstrate that while the energy of the four-neutron system may be compatible with the experimental value, its width must be larger than the reported upper limit, supporting the interpretation of the experimental observation as a reaction process too short to form a nucleus.
由于文献[1]中最近报道的实验线索，对共振四中子系统的搜寻得以重启。这样一个系统的存在将深刻影响我们对核物质的理解，因此需要进行严格的研究。在这项工作中，我们使用具有各种两体手征相互作用的从头算技术，在准定态形式体系中研究四中子共振的存在。我们采用无芯伽莫夫壳层模型和密度矩阵重整化群方法，二者均辅以自然轨道的使用以及一种用于宽共振的新识别技术。我们证明，虽然四中子系统的能量可能与实验值相符，但其宽度必须大于报道的上限，这支持了将实验观测解释为一个太短而无法形成原子核的反应过程的观点。
