Short-lived Pear Shaped Atomic Nuclei Observed at CERN

Posted on May 9, 2013

Pear Shaped Nuclei Image


An international team at the ISOLDE radioactive-beam facility at CERN has shown that some atomic nuclei can assume asymmetric, pear-like shapes. Most nuclei that exist naturally are not spherical but have the shape of a rugby ball. The pear-shaped nuclei have more mass at one end of the nucleus than the other. A technique pioneered at ISOLDE has been used successfully to study the shape of these short-lived isotopes Radon 220 and Radium 224.

Professor Peter Butler, from the University's Department of Physics, (pictured below) who carried out the measurements, said in a statement, "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."

Peter Butler and Pear Shaped Nuclei Sketch


Tim Chupp, a University of Michigan professor of physics and biomedical engineering and co-author of the research paper, says the findings could help explain why the Big Bang created more matter than antimatter. Chupp says in a statement, "If equal amounts of matter and antimatter were created at the Big Bang, everything would have annihilated, and there would be no galaxies, stars, planets or people."

The research was published here in the journal nature.

Photo: Liam Gaffney and Peter Butler, University of Liverpool