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.

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 July 23, 2014 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 July 23, 2014).

Share This




More Matter & Energy News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Robot Parking Valet Creates Stress-Free Travel

Robot Parking Valet Creates Stress-Free Travel

AP (July 23, 2014) — 'Ray' the robotic parking valet at Dusseldorf Airport in Germany lets travelers to avoid the hassle of finding a parking spot before heading to the check-in desk. (July 23) Video provided by AP
Powered by NewsLook.com
Boeing Ups Outlook on 52% Profit Jump

Boeing Ups Outlook on 52% Profit Jump

Reuters - Business Video Online (July 23, 2014) — Commercial aircraft deliveries rose seven percent at Boeing, prompting the aerospace company to boost full-year profit guidance- though quarterly revenues missed analyst estimates. Bobbi Rebell reports. Video provided by Reuters
Powered by NewsLook.com
Europe's Car Market on the Rebound?

Europe's Car Market on the Rebound?

Reuters - Business Video Online (July 23, 2014) — Daimler kicks off a round of second-quarter earnings results from Europe's top carmakers with a healthy set of numbers - prompting hopes that stronger sales in Europe will counter weakness in emerging markets. Hayley Platt reports. Video provided by Reuters
Powered by NewsLook.com
9/11 Commission Members Warn of Terror "fatigue" Among American Public

9/11 Commission Members Warn of Terror "fatigue" Among American Public

Reuters - US Online Video (July 22, 2014) — Ten years after releasing its initial report, members of the 9/11 Commission warn of the "waning sense of urgency" in combating terrorists attacks. Mana Rabiee 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
from the past week

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