Seminarium Fizyki Wielkich Energii

The GERDA detector, installed in the underground laboratory at Gran Sasso (LNGS) in Italy, has been designed to search for neutrino-less double beta decay (0vbb) of 76Ge. Observation of this process would mean, among other things, that the lepton number is not conserved and would imply physics beyond the Standard Model. In GERDA high-purity Germanium (HPGe) detectors enriched in the isotope 76Ge are used. They are directly immersed in the radio-pure liquid argon, which acts as a passive and an active shield, and as a cooling medium for the detectors, simultaneously. Very recently a new half-life limit on the 0vbb decay of 76Ge of T1/2 > 8 x10^{25} y has been obtained. The background rate in the energy region of interest is so low that < 1 count is expected within the anticipated life time of the experiment. Thus GERDA is the first background-free detector devoted to searches for the 0vbb decay with high discovery potential. The design, the importance of the achieved results, and the perspectives of GERDA will be discussed.