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 Tune your radio: galaxies sing while forming stars
21.02.2017 | Max-Planck-Institut für Radioastronomie

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>