Resumen de The Problem of Cosmogenic Activation in Double Beta Decay Experiments
Susana Cebrián Guajardo 
Large efforts are being devoted to the detection of the neutrinoless nuclear double beta decay since this process is a probe to investigate the lepton number violation and the Dirac or Majorana nature of the neutrino, as well as to measure the absolute scale of the neutrino mass spectrum. Since double beta decay is a rare process, experiments with an ultra-low background are mandatory to attempt its detection; for this reason, double beta decay experiments are installed in underground laboratories. Activity induced in detectors and materials of the experimental set-up by he exposure to cosmic rays when being above ground gives a significant contribution o the background. The main difficulty to study quantitatively the problem of cosmic activation in double beta decay experiments is the lack of accurate information (either from measurements or from calculations) on the cross-sections of isotope production in the targets of interest. Here, an overview of data libraries and computational codes (following different approaches) to be used in these studies of cosmogenic activation is given. Results on isotope production cross sections for the particular case of germanium detectors have been collected and elaborated; for the production of 68Ge in 76Ge (the most relevant pair of product-target in enriched germanium detectors) differences from the several estimates reach up to a factor ~50. It can be concluded that experimental measurements of production cross sections in the specific targets of interest for Double Beta Decay and further development on models and codes are still necessary to be able to make accurate estimates of activation yields.
