Physicists ‘tickle’ anti-atoms to find new limit on anti-hydrogen atom

New research published today in Nature magazine reveals an improved limit on the charge of the anti-hydrogen atom which advances understanding as to why antimatter vanished from the early Universe.

Inside the ALPHA apparatusPhysicists from Swansea University’s College of Science together with colleagues from the international ALPHA collaboration at CERN show in their research that the improved limit was obtained by "tickling" the anti-atoms while they were held in a magnetic bottle.

Electrically tickling the atoms would lead, if they had a charge, to an expulsion of the atoms from the magnetic bottle. As no atoms escaped, the researchers concluded that the limit on the possible charge of the anti-hydrogen atom at less than about one billionth of that of an electron.

The current research is part of a wide effort by many researchers to study antimatter in detail to unravel why it disappeared from the early Universe. Anti-atoms are the closest scientists can get in the laboratory to create conditions as they would be in an antimatter Universe, and thus studying their properties is key to unravelling this mystery. 

Atoms are known to be electrically neutral, but anti-atoms have only recently become available for study, in particular by the pioneering efforts of Swansea physicists and the ALPHA collaboration. The lack of antimatter for study is one of the most profound mysteries in physics today, as the current understanding is that a Universe made entirely from antimatter would be essentially indistinguishable from one made of matter. However, the Universe seems devoid of antimatter in bulk.

Professor Madsen from Swansea's physics department says "We we have done is trying to tickle the anti-atoms to reveal any signs of a charge, and we have seen no response - so, until now, the antimatter is holding its cards very tight indeed. We are planning more precise measurements looking at the details of the atomic structure this year."

Read the research here

Watch the ALPHA experiment animation

Image courtesy of CERN