A systematic search for step-like anomalies in the tritium \beta-decay   spectrum in the Troitsk-\nu-mass experiment
  The issue of step-like anomalies in the tritium \beta-decay spectrum as measured in the Troitsk-\nu-mass experiment is addressed in the context of the new analysis in a systematic fashion using efficient statistical tests specifically derived for the purpose. It is concluded that the presence of the anomaly cannot be statistically asserted with a high confidence level. 
A. V. Lokhov, F. V. Tkachov and P. S. Trukhanov
hep-ex hep-ph