Featured Research

from universities, journals, and other organizations

Scientists demonstrate pear shaped atomic nuclei

Date:
May 9, 2013
Source:
University of Liverpool
Summary:
Scientists have shown that some atomic nuclei can assume the shape of a pear which contributes to our understanding of nuclear structure and the underlying fundamental interactions.

Scientists at the University of Liverpool have shown that some atomic nuclei can assume the shape of a pear which contributes to our understanding of nuclear structure and the underlying fundamental interactions.

Related Articles


Most nuclei that exist naturally are not spherical but have the shape of a rugby ball. While state-of-the-art theories are able to predict this, the same theories have predicted that for some particular combinations of protons and neutrons, nuclei can also assume very asymmetric shapes, like a pear where there is more mass at one end of the nucleus than the other.

The experimental observation of nuclear pear shapes is important for understanding the theory of nuclear structure and for helping with experimental searches for electric dipole moments (EDM) in atoms.

The Standard Model of particle physics predicts that the value of the EDM is so small that it lies well below the current observational limit. However, many theories that try to refine this model predict EDMs that should be measurable. In order to test these theories the EDM searches have to be improved and the most sensitive method is to use exotic atoms whose nucleus is pear-shaped. Quantifying this shape will therefore help with experimental programmes searching for atomic EDMs.

Professor Peter Butler, from the University's Department of Physics who carried out the measurements, said: "Our findings contradict some nuclear theories and will help refine others. The measurements will also help direct the searches for atomic EDMs currently being carried out in North America and in Europe, where new techniques are being developed to exploit the special properties of radon and radium isotopes.

"Our expectation is that the data from our nuclear physics experiments can be combined with the results from atomic trapping experiments measuring EDMs to make the most stringent tests of the Standard Model, the best theory we have for understanding the nature of the building blocks of the universe."

Most nuclear isotopes predicted to have pear shapes have been out of reach of experimental techniques to measure them.

Now, at the ISOLDE facility at CERN, beams of very heavy, radioactive nuclei can be produced in high-energy proton collisions with a uranium carbide target. They are then selectively extracted using their chemical and physical properties before being accelerated to 8% of the speed of light and allowed to impinge on a target foil of isotopically pure nickel, cadmium or tin.

When this happens the relative motion of the heavy accelerated nucleus and the target nucleus creates an electromagnetic impulse that excites the nuclei. By studying the details of this excitation process it is possible to understand the nuclear shape.

This method has been used successfully to study the shape of short-lived isotopes 220Rn and 224Ra. The data show that while 224Ra is pear-shaped, 220Rn does not assume the fixed shape of a pear but rather vibrates about this shape.


Story Source:

The above story is based on materials provided by University of Liverpool. Note: Materials may be edited for content and length.


Journal Reference:

  1. L. P. Gaffney, P. A. Butler, M. Scheck, A. B. Hayes, F. Wenander, M. Albers, B. Bastin, C. Bauer, A. Blazhev, S. Bφnig, N. Bree, J. Cederkδll, T. Chupp, D. Cline, T. E. Cocolios, T. Davinson, H. De Witte, J. Diriken, T. Grahn, A. Herzan, M. Huyse, D. G. Jenkins, D. T. Joss, N. Kesteloot, J. Konki, M. Kowalczyk, Th. Krφll, E. Kwan, R. Lutter, K. Moschner, P. Napiorkowski, J. Pakarinen, M. Pfeiffer, D. Radeck, P. Reiter, K. Reynders, S. V. Rigby, L. M. Robledo, M. Rudigier, S. Sambi, M. Seidlitz, B. Siebeck, T. Stora, P. Thoele, P. Van Duppen, M. J. Vermeulen, M. von Schmid, D. Voulot, N. Warr, K. Wimmer, K. Wrzosek-Lipska, C. Y. Wu, M. Zielinska. Studies of pear-shaped nuclei using accelerated radioactive beams. Nature, 2013; 497 (7448): 199 DOI: 10.1038/nature12073

Cite This Page:

University of Liverpool. "Scientists demonstrate pear shaped atomic nuclei." ScienceDaily. ScienceDaily, 9 May 2013. <www.sciencedaily.com/releases/2013/05/130509104352.htm>.
University of Liverpool. (2013, May 9). Scientists demonstrate pear shaped atomic nuclei. ScienceDaily. Retrieved January 28, 2015 from www.sciencedaily.com/releases/2013/05/130509104352.htm
University of Liverpool. "Scientists demonstrate pear shaped atomic nuclei." ScienceDaily. www.sciencedaily.com/releases/2013/05/130509104352.htm (accessed January 28, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Wednesday, January 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Brand Blocker' Glasses Blur Ads in Real Time

'Brand Blocker' Glasses Blur Ads in Real Time

Buzz60 (Jan. 28, 2015) — A team of college students design and build a pair of goggles that will obscure any corporate branding from your field of vision. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
Powered by NewsLook.com
Amplifying Tiny Movements to Visualize the Invisible

Amplifying Tiny Movements to Visualize the Invisible

Reuters - Innovations Video Online (Jan. 28, 2015) — A new video recording method that amplifies seemingly invisible motion could lead to a touch-free vital signs monitor, and offer a new tool for engineers to gauge stresses on bridges and tunnels in real time. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Boeing's Profit Soars

Boeing's Profit Soars

Reuters - Business Video Online (Jan. 28, 2015) — Boeing delivered more commercial planes, especially 737s and 787s, fueling profit. But it issued a mixed outlook. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Robot Replacements for Foxconn's Workers

Robot Replacements for Foxconn's Workers

Reuters - Business Video Online (Jan. 28, 2015) — Foxconn parent Hon Hai Precision Industry is looking to automation to keep productivity up without the rising costs of human labor. Meg Teckman reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


Exotic Atoms Hold Clues to Unsolved Physics Puzzle at the Dawn of the Universe

May 8, 2013 — An international team of physicists has found the first direct evidence of pear shaped nuclei in exotic atoms. The findings could advance the search for a new fundamental force in nature that could ... read more

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins