A New Tool in Nuclear Physics: Nuclear Lattice Simulations

摘要

The nuclear many-body problem continues to be one of the most interesting and demanding challenges in contemporary physics. With the advent of FAIR, FRIB, and the many existing radioactive ion beam facilities, a detailed and accurate theoretical understanding of nuclear structure and reactions is mandatory. A major breakthrough in nuclear theory was initiated through the work of Steven Weinberg [1], who made the first steps for an effective field theory (EFT) solution of the nuclear force problem. In this approach, two- and multi-nucleon forces as well as the response to external electromagnetic and weak probes can be calculated systematically, precisely, and consistently. In addition, the so important issue of assigning theoretical errors can be dealt with naturally. The very hot topic of the quest for three-nucleon forces was already addressed in this journal [2], which also contained a short introduction into the framework of chiral nuclear EFT. In this scheme, the nuclear forces are given in terms of one-, two-,... pion exchanges and smeared local multi-nucleon operators, that parameterize the short-distance behavior of the nuclear forces. These operators come with unknown coupling constants, the so-called low-energy constants (LECs) that must be determined from a fit to nucleon-nucleon scattering and a few three-body data. For systems up to four nucleons, these forces have been tested in extensive detail and scrutinized. One of the present research foci is the calculation and investigation of higher order corrections to the three-nucleon forces as well as the construction of electroweak current operators. For reviews on the method and many results see Refs. [3, 4].