ALPHA physicists explore the effect of gravity on antimatter

Physicists from Swansea University have collaborated on research published this week in Nature Communications, describing the first direct analysis of how antimatter is affected by gravity to help gain more understanding about how the Universe works.

Professor Mike Charlton, Dr Stefan Eriksson, Dr Niels Madsen, Dr Dirk van der Werf, postdoctoral researcher Dr Aled Isaac and student Silvia Napoli of the University’s College of Science are part of a team of scientists from the ALPHA  (Antihydrogen Laser Physics Apparatus) collaboration at CERN (the European Organisation for Nuclear Research) publishing research marking an important step towards the understanding of the behaviour of antimatter.

Current thinking holds that antimatter and matter should behave gravitationally in the same way:  matter and antimatter experience the same force originating from earth’s gravitational field. However no direct measurements exist that can rule out the possibility that they do not.

Now the ALPHA scientists are working on just such an experiment by trapping antihydrogen atoms and then releasing them, to find if antimatter and matter respond identically to gravity; this has allowed them to put a limit on anomalous gravitational effects.

Dr van der Werf said: “The findings of this direct experimental test are important because it is the first step towards answering some key questions about the nature of the Universe. We will be continuing our experiments with the ALPHA team in 2014 to gain more data and we hope to test whether antimatter responds to gravity by falling down. Although it is unlikely, if we find that antimatter falls upward, we would have to rethink our views on the way that the Universe works.”

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