Nuclear Physics(DNP)
Physique nucléaire (DPN)
Walter OELERT
Forschungszentrum Juelich
Observation of Cold Antihydrogen - Perspectives for Testing Fundamental Symmetries
The ATRAP experiment at the CERN antiproton decelerator AD aims for a test of the CPT invariance by a comparison of the hydrogen to anti-hydrogen atom spectroscopy. To achieve the required high precision in the measurements of atomic transitions cold atoms of anti-hydrogen are essential. Trapped neutral anti-hydrogen atoms, up to now not available, have to be used.
The anti-hydrogen production via 3-body recombination routinely operated at ATRAP[1,2] is studied in more detail in order to characterize this production mechanism in view of future trapping of neutral anti-hydrogen atoms. Shape parameters of the antiproton and positron clouds and the anti-hydrogen production probability as a function of relevant parameters have been measured. The N-state distribution of the produced Rydberg anti-hydrogen was analyzed and first measurements of the anti-hydrogen velocity have been performed. Furthermore an alternative production mechanism via double charge exchange has been studied[3]. The results achieved in 2003 and further steps towards the trapping of anti-hydrogen atoms will be discussed.
1. G. Gabrielse et al., Phys. Rev. Lett. 89, 213401 (2002).
2. G. Gabrielse et al., Phys. Rev. Lett. 89, 233401 (2002).
3. E. A. Hessels et al., Phys. Rev. A 57, 1668 (1998).