The shapes in the atomic nucleus communicate with each other in a different way than the scientists have thought till now

Research, Science, CERN

Added by: A. Nozdrovická, 26.5.2020, 512 visits


The results at the very edge of knowledge are mostly achieved in large-scale international co-operation. The scientific disciplines, where this cooperation started at all and has probably reached the highest level, are the nuclear and subnuclear physics. Therefore, it is not unusual for collaborations with several thousand scientists from all over the world to work on large experiments at CERN, for instance.

An example of the international collaboration of smaller but important scope is the work which the international team under the guidance of the Institute of Physics SAS published in these days in a journal called Physics Letters B.

“We have studied the unstable atomic nuclei 177,179Au and came to interesting results, which give us the answer for the question in what way the different shapes that the atomic nucleus can create “communicate” with each other. We already know that the atomic nuclei are the examples of a system which follows the laws of the quantum mechanics. For such systems, the existence of excited states that carry information about the structure and properties of the matter that forms the atomic nucleus is characteristic. The atomic nucleus can assume different shapes. In general, states with different shapes, e.g. round and the shape of the British rugby ball "don't like each other very much". It means that they are very reluctant to change into each other and prefer to change to a similar shape. But in the unstable atomic nuclei which we have studied, we found out that there is a state which changes into two completely different shapes with roughly similar probability. The explanation for this is that this state is the example of the so-called Schrödinger's cat, therefore, is likely to occur in one or the other shape. Only when the radiation detectors “look” at it, it will choose the shape which it will show us, "said Martin Venhart, head of the research project from the Institute of Physics SAS.

We won´t find the unstable atomic nuclei 177,179Au on Earth, therefore, it is necessary to prepare them in laboratories. The scientists from various institutions of the four continents of the world have carried out an experimental part of the work in the cyclotron laboratory of the University of Jyväskylä in Finland. A total of 24 days of the measuring time on the cyclotron was needed, divided into two campaigns.

“One hour of the accelerator´s work and the whole support infrastructure costs several thousand euros. The measuring time is allocated in a competitive manner on the basis of the submitted proposals. The final decision on the allocation, or rejection, is in the hands of the international panel. The group from the Institute of Physics SAS prepared and submitted both proposals of experiments, which were approved in full scope, carried out both experiments in Finland and led the international team that analysed the measured data. In this context, I would like to say that it is not only us, the nuclear physicists, who are very pleased that the support of international scientific cooperation has appeared in the government's program statement, "said Martin Venhart.

The journal Physics Letters B is narrowly specialised in the nuclear and subnuclear physics and cosmology and publishes important new findings within these disciplines. Among the significant results which were published here in the relatively recent past, the discovery of the Higgs boson by the ATLAS and CMS experiments at CERN can be mentioned. This discovery, which is also credited to scientists from the Institute of Experimental Physics SAS, led to the Nobel Prize award to theoretical physicists who predicted the existence of this particle.

Monika Tináková

Photo: archiv MV

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