Niels Bohr Lecture by Jeffrey Hangst

Jeffrey Hangst, Institut for Fysik og Astronomi, Aarhus Universitet og CERN.

Antihydrogen - Stable, Neutral Antimatter

What would you do if you could get your hands on some neutral, stable antimatter? No matter what you may have seen in the cinema, blowing up the Vatican is not an option - trust me on this.

In 2010, the ALPHA experiment at CERN demonstrated [1] that it is indeed possible to capture and hold atoms of antihydrogen - element number -1 on the periodic table. We have been producing antihydrogen in quantity at CERN since 2002, when the ATHENA experiment showed how to synthesize it from cold clouds of antiprotons and positrons [2].

In this lecture I will discuss how to make antihydrogen, and then I will describe the many additional steps necessary to be able to trap and hold it. With antihydrogen held for questioning, we can now address what has long been one of the most intriguing remaining questions about nature: Do atoms of matter and antimatter obey the same laws of physics? I will describe how we in ALPHA plan to tackle this question.

1. Andresen, G.B. et al., Trapped Antihydrogen, Nature 468, 673 (2010).
2. Amoretti, M. et al., Production and detection of cold antihydrogen atoms. Nature 419, 456 (2002).

Jeffrey S. Hangst, Aarhus University, Spokesperson. The ALPHA Collaboration