Osaka, Japan – Scientists at Osaka University’s Department of Physics and Nuclear Physics Research Center (RCNP), in collaboration with Kyoto University, used inelastic alpha particle scattering to show that the The theoretical “condensed state 5α” does indeed exist in neon. 20. This work could help us to better understand N-body low density nucleon systems.
All the elements besides hydrogen and helium must have been fused inside a star’s nuclear furnace. The yield during these reactions of carbon 12, which has six protons and six neutrons, is increased in an unusual quirk in that 12 is divisible by 4. This means that with a little extra energy the nucleons of carbon can form three alpha particles. , composed of two protons and two neutrons each, and these alpha particles can be condensed in the lower-energy orbit of carbon-12. The existence of a condensed alpha state in heavier isotopes with atomic weights divisible by four, such as neon-20, has been theorized, but remains uncertain. These condensed states would provide a unique window into the world of nuclear physics. This is because the densities of most normal nuclei are very similar to each other, while the alpha condensed state would be an example of a low density many-body system. Measuring the properties of protons and neutrons in such a diluted state would be very useful in understanding the nature of the low density nuclear matter that exists on the surface of neutron stars.
Now, a team of researchers led by Osaka University have provided experimental evidence that these excited states exist in neon-20. By shooting alpha particles at a neon gas, they observed that the decay products indicated the existence of specific energy states in the original nucleus. These corresponded very well to the predictions of the condensed state 5 ,, in which the 10 protons and 10 neutrons are grouped into five alpha particles on the orbit of lower energy.
“We were able to get such accurate results because we were able to measure the decay particles from the excited state,” says first author Satoshi Adachi. “We have developed an isotope-enriched neon-20 gas target system with an ultra-thin SiNx gas seal window. selectively excited. This measurement was very difficult, but a high quality beam provided by the well-tuned cyclotrons of the RCNP allowed us to achieve it. These techniques allowed scientists to perform a detailed comparison between the calculations of the statistical decay model and the experiment.
“We expect this research to accelerate progress in our understanding of extreme environments, such as the surface of a neutron star,” said lead author Takahiro Kawabata. The work can also be extended to even heavier isotopes which follow the “divisible by four” scheme.
The article “Candidates for the condensed state 5α in 20Ne “was published in Physics Letters B at DOI: https: /
About Osaka University
Osaka University was founded in 1931 as one of the Seven Imperial Universities of Japan and today is one of the leading comprehensive universities in Japan with a broad disciplinary spectrum. This strength is coupled with a desire for singular innovation that extends throughout the scientific process, from fundamental research to the creation of applied technologies with positive economic impacts. Its commitment to innovation has been recognized in Japan and around the world, being named the most innovative university in Japan in 2015 (Reuters 2015 Top 100) and one of the most innovative institutions in the world in 2017. (Innovative Universities and Nature Index Innovation 2017). Today, Osaka University is leveraging its role as a designated national academic society selected by the Ministry of Education, Culture, Sports, Science and Technology to contribute to innovation for the human well-being, the sustainable development of society and social transformation. Website: https: /
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