Pear-Shaped Atoms May Hold The Key To Understanding The Antimatter Imbalance

Scientists believe they have found a clue to unlocking a decades old question: when the Big Bang occurred, why was there more matter than antimatter created? The pear shaped nuclei of certain exotic atoms may hold the key.

Antimatter is basically the exact opposite of matter, particles with the same mass, but opposite charges. When matter and antimatter come into contact with each other, they essentially cancel each other out. What scientists are curious about is why there was a significant enough imbalance between the amount of matter and antimatter created that we ended up with a universe made almost entirely out of the former.

"If equal amounts of matter and antimatter were created at the Big Bang, everything would have annihilated, and there would be no galaxies, stars plants or people," said Tim Chupp, a University of Michigan professor of physics and biomedical engineering.

The difficulty in figuring out this imbalance is due to the fact that the Standard Model, which allows us to understand how matter behaves, did not predict this phenomenon. Scientists are now looking at measurements of how the axis of nuclei of radon and radium line up with their spin.

The nuclei of these two atoms are unique in that they are pear shaped, instead of the sphere like or elliptical shapes of other atoms. This is due to positive protons being pushed away from he center of the nucleus by nuclear forces, forces fundamentally different from spherically symmetrical ones like gravity.

This interaction may prove to be a major boon in understanding the antimatter-matter imbalance.

"It produces the matter/antimatter asymmetry in the early universe and it aligns the direction of the spin and the charge axis in these pear-shaped nuclei," Tim Chupp stated. "Our findings contradict some nuclear theories and will help refine others."

Scientists may now turn their attention towards searching for atomic "electric dipole moments" (EDMs), which would allow them to further study the special properties of radon and radium.

The study was published in the journal Nature.