Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A new window for the study of exotic atomic nuclei.

29.01.2004


On Friday the 30th, during the XLII international winter meeting on nuclear physics at Bormio, the first results will be announced of Finuda experiment (Nuclear Physics at Daphne), settled in Frascati at Infn National Laboratories.



Planned and made operating by a group of about forty physicists from Universities and Infn Sites of Bari, Brescia, Frascati, Pavia, Torino and Trieste, Finuda is devoted to the study of hypernuclei: nuclei composed by three different kinds of particles rather then two (protons and neutrons) as in ordinary nuclei.

The first stage of the experiment started on October the15th and the data obtained up to now promise to be the most relevant in the study of hypernuclei since their discovery occurred in 1953 thanks to the Polish physicists Marian Danysz e Jerzy Pnieswski. “The study of hypernuclei opens a favoured window to understand some aspects of the strong force and the weak force which, with electromagnetic and gravitational forces, complete the whole of the four fundamental forces in nature” says Sergio Bertolucci, director of the National Laboratories of Frascati.


Hypernuclei are the result of an alteration of a normal atomic nucleus, obtained hitting an ordinary nucleus through a particle named K meson. In the collision between K mesons and nucleus, one of the particles that composes the nucleus, that is to say a proton or a neutron, is substituted by another particle named lambda. While protons and neutrons are composed by such quarks named up and down, the lambda particle contains a third type of quark named strange. This one is provided with a greater mass rather than the one of up quark and down and it is considered it was plentiful in the very first instants of universe life.

New information about the structure of atomic nuclei can be obtained studying the way the lambda particle localizes inside nucleus. Protons and neutrons are in fact joined inside nucleus by the so-called strong force, but they go through the effects of Pauli exclusion principle, which prevents identical particles, such as two protons or two neutrons, from locating inside nucleus in the same energy level (energy levels depend on how near to the centre of nucleus they are). But in a hypernucleus there is only one lambda particle, so it is free from the effects of exclusion principle and when it localizes inside nucleus, it is subject only to the strong nuclear force.

A second kind of interesting information comes from the fact that the lambda particle is unstable: it tends to decay in a very short time, retransforming itself in a proton or a neutron. This is due to the weak interaction: one of the four fundamental forces, the same which origins the natural radioactivity.

Nevertheless, if the lambda particle is embedded in the nucleus, the presence of protons and neutrons and the Pauli principle prevent it from decaying in the usual ways. Therefore, it must interact with the other components of the nucleus before retransforming in a proton or a neutron. It’s just studying these mechanisms that Finuda can clear up some aspects of the weak interaction till now unexplored.

“Finuda has been planned to study both formation of hypernuclei and their decaying and this makes it an innovative experiment”, says Tullio Bressani, national spokesman of Finuda experiment.

The hypernuclei studied by Finuda are produced thanks to the accelerator named Dafne at Frascati National Laboratories. Dafne permits collisions between electrons and positrons creating, as a final product of a series of transformations, the K mesons.

“Despite the great interest of hypernuclei study, it proceeded slowly until some years ago, because of the great difficulties occurred in producing a satisfactory number of them” explains Tullio Bressani, “foreign laboratories, in the United States and above all in Japan, have recently made a notable experimental effort in this research field, but even more significant has been the one made in Italy at Frascati National Laboratories of Infn.

The only initial phase of data recording, which will continue for about three months, will allow to produce many hundreds of thousands of hypernuclei, more or less the same quantity obtained and observed in the first fifty years since their discovery”. The success of the experiment is also a success of Italian research: “Finuda is attracting to our country, and in particular to the laboratories of Frascati, the best researchers in the world in the field of hypernuclei physics”, concludes Sergio Bertolucci.

Barbara Gallavotti | alfa
Further information:
http://www.infn.it

More articles from Physics and Astronomy:

nachricht Quantum gas turns supersolid
23.04.2019 | Universität Innsbruck

nachricht Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun
18.04.2019 | University of Warwick

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

Marine Skin dives deeper for better monitoring

23.04.2019 | Information Technology

Geomagnetic jerks finally reproduced and explained

23.04.2019 | Earth Sciences

Overlooked molecular machine in cell nucleus may hold key to treating aggressive leukemia

23.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>