With the WASA detector, a very special instrument is currently being set up at GSI/FAIR. Together with the fragment separator FRS, it will be used to produce and study so-called hypernuclei during the upcoming experiment period of FAIR Phase 0 in 2022. For this purpose, the assembly, which weighs several tons, is being transferred to the facility in a complex installation procedure. The scientific relevance of the planned experiments with hypernuclei is also shown by a recent review article in the scientific journal "Nature Reviews Physics", in which GSI/FAIR researchers play a leading role.
Very special exotic nuclei are in the focus of researchers in the upcoming experiment period: so-called hypernuclei. Regular atomic nuclei are made of protons and neutrons, which in turn are composed of a total of three up and down quarks. If one of these quarks is replaced by another type, a so-called strange quark, a hyperon is formed. Atomic nuclei that contain one or more hyperons are called hypernuclei. They can be produced in particle collisions at accelerators, and their decay can then be observed in experiment setups such as the WASA detector and the FRS in order to study their properties in detail.
Professor Takehiko Saito, leading scientist in the GSI/FAIR research pillar NUSTAR, is the first author of the paper "New directions in hypernuclear physics" in the journal Nature Reviews Physics, which highlights previous results, open questions and new possibilities in the field of hypernuclear research. "Hypernuclei could shed light on what happens inside neutron stars. According to current predictions, hypernuclei should exist there abundantly. However, some of their properties have not yet been accurately determined. Among other things, the researchers want to determine the binding energy and lifetimes of different hypernuclei more precisely in future experiments, as well as discover new variations," Saito says. "For this purpose, the HypHI experiment, previously operated at GSI/FAIR, has already achieved exciting results, but has now reached its limits. The combination of WASA and FRS promises new insights and information. The detector has a higher detection efficiency for measuring all the decay products of the hypernuclei. In the future, the FAIR facility, which is currently being built, will also open up extensive new opportunities for the study of hypernuclei."
