In English

Three-Nucleon Forces Through Normal-Ordered Approximations

Dag Fahlin Strömberg
Göteborg : Chalmers tekniska högskola, 2016. 44 s.
[Examensarbete på avancerad nivå]

Three-body forces have long been known to play an important role in nuclear physics. However, fully including such interactions in ab-initio methods is computationally expensive and not feasible for larger nuclei. As an alternative, approximations based on normal-ordering with respect to a Fermi state of the nucleus can be used. In this framework part of the three-body interaction can be expressed as lower order interactions, which can be included without increasing the computational complexity. This thesis provides a full derivation of the normal-ordered two-body (NO2B) approximation for closed-shell nuclei. In addition, a simple implementation of this method is described. This is then used to calculate ground states of helium-4 in small model spaces, which are compared to the corresponding calculations with full three-body forces. The results show a relative error of less than 1.5%, in line with earlier studies.

Nyckelord: ab-initio, nuclear physics, normal-ordered approximation, quantum manybody theory, three-nucleon forces

Publikationen registrerades 2016-11-02. Den ändrades senast 2016-11-02

CPL ID: 244698

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