Jeffrey S. Hangst<br>

Department of Physics and Astronomy
University of Aarhus, Denmark<br>

<i>The Production of Cold
        Antihydrogen</i><p>

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Antihydrogen is the antimatter equivalent of the hydrogen atom.  It 
is of fundamental interest for, among other things, tests of CPT 
symmetry and measurements of gravitational effects on antimatter.  In 
2002 the ATHENA  experiment succeeded both in synthesizing cold 
antihydrogen atoms from trapped plasmas of positrons and antiprotons, 
and in detecting the annihilation of the anti-atoms when they escaped 
the apparatus.  In this colloquium I will describe the ATHENA 
experiment and the developments that resulted in this success.  I 
will also discuss subsequent experiments aimed at understanding the 
physics of antihydrogen production, and the future of antihydrogen 
physics will be addressed.  If time permits I will share some 
anecdotes about the media frenzy which resulted from ATHENA's 
announcement of the first production of cold anti-atoms.<p>

ref: M. Amoretti et al., Nature 419, 456 (2002)


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