author={H. V. Klapdor-kleingrothaus and Alexander Dietz and Hanns Ludwig Harney and Irina Vladimirovna Krivosheina},
  journal={Modern Physics Letters A},
The data of the Heidelberg–Moscow double beta decay experiment for the measuring period August 1990–May 2000 (54.9813 kg y or 723.44 molyears), published recently, are analyzed using the potential of the Bayesian method for low counting rates. First evidence for neutrinoless double beta decay is observed giving first evidence for lepton number violation. The evidence for this decay mode is 97% (2.2σ) with the Bayesian method, and 99.8% c.l. (3.1σ) with the method recommended by the Particle… 

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