Klapdor's claim for the observation of the neutrinoless double beta-decay of Ge-76. Analysis and corrections

Abstract

Heidelberg-Moscow Collaboration experimental data [1-4] with the claim for the observation of the neutrinoless double beta-decay of Ge-76 has been carefully analyzed. The analysis gave an evidence that the observed 2039 kev line in the full spectrum was produced by overlapping of three unresolved peaks: ~2035.5 kev, ~2037.5 kev and ~2039.5 kev. It was indicated that the 2035.5 kev and 2039.5 kev peaks were produced by the double-coincidences of gamma-quanta in the detectors. Existence of the two background gamma-peaks at ~2035.5 kev and ~2039.5 kev was confirmed by an analysis of the background measurements with low-background Ge detectors with an active shielding [5-7]. The 2037.5 kev line could be the expected 2{\beta}0{\nu}-decay transition of 76Ge according to the results of the improved pulse-shape analysis. Position of the line, 2037.56+/-0.56(stat)+/-1.2(syst) kev [4], was slightly below the expected, E2{\beta}=2039.0+/-0.05 kev [8], but still within a limit for poor statistics. The most accurate value of its intensity was extracted from the 51.39 kg \cdot y data with PSA: number of events 12.4+/-3.7 and T1/2=1.98 \cdot 1025 years [2,3].