COLD ANTIHYDROGEN AT ATHENA: EXPERIMENTAL OBSERVATION AND BEYOND

摘要

The experimental production and detection of cold antihydrogen atoms reported by the ATHENA Collaboration in 2002 represents a major step toward the study of the antiatom internal structure. The availability of a high num-ber of antihydrogen atoms in a cryogenic environment is the key ingredient for a series of stringent tests of the CPT symmetry and of the gravitational weak equivalence principle that is foreseen on neutral antimatter. The experimental apparatus and the method used by ATHENA present some unique features that are first introduced. Then the absolute rate of antihydrogen production and the signal to background ratio in ATHENA are discussed, along with some preliminary results regarding the temperature dependence of antihydrogen production. Finally the future perspectives for laser spectroscopy of antihydrogen are briefly outlined.