Abstract :
The simplest electrical neutral system made entirely of antimatter is the antihydrogen atom (View the MathML source) consisting of a positron (e+) orbiting an antiproton (View the MathML source). The first View the MathML source atoms produced in View the MathML source collisions at the Low Energy Antiproton Ring (LEAR) at CERN have been observed in 1995 [G. Baur, et al., Phys. Lett. B 368 (1996) 251] and were confirmed thereafter at Fermilab [G. Blanford, et al., Phys. Rev. Lett. 80 (1998) 3037]. However, low production rates and high velocity of these exotic atoms made it impossible to even think of using them for high precision spectroscopy or studies of the gravitational interaction.
At the Antiproton Decelerator (AD) of CERN trap experiments are in operation, where cold View the MathML source atoms are synthesized "at rest" starting from clouds of View the MathML sourceʹs and e+ʹs trapped at temperatures of a few Kelvin. Only if the produced View the MathML source atoms once are trapped in a magnetic field arrangement meaningful studies can be done. The challenging prospect is the comparison of atomic transitions in antihydrogen and hydrogen atoms where the latter have been measured with highest precision [R. Holzwarth, et al., Phys. Rev. Lett. 85 (2000) 2264, M. Niering, et al., Phys. Rev. Lett. 84 (2000) 5496]
Within local relativistic quantum field theories CPT is an exact symmetry which predicts absolutely identical spectral lines and thus any deviation in the spectroscopy of antimatter from matter atoms would require an extension of the standard model by CPT violation components.
Thus, such precision experiments just have to be done and here a report is presented on first steps towards the production of cold View the MathML source atoms and subsequent studies of their physics properties.
