Search for anomalies in the decay of radioactive Mn-54

Recent papers have reported that Mn-54, which decays by electron capture (a weak nuclear interaction) with half-life similar to 312 days, is influenced by solar activity. Should this actually occur, new physics would be needed to explain it. This paper reports results of an analysis of Mn-54 activity measured over a time interval of similar to 3.6 half-lives. If standard nuclear physics applies, the logarithmic residuals of Mn-54 activities should form a stationary set of independent random variables whose statistics are determined solely by a constant decay rate lambda and initial mean count mu. Analysis of the time-variation, autocorrelation, and power spectra of the Mn-54 logarithmic residuals agrees exquisitely with standard nuclear physics. Computer-simulated activities exhibiting periodic decay of amplitude A = alpha lambda show that anomalies would be detectable by these statistical tests for values of a as low as similar to 1 part in 10(4). This limit is about 10 times lower than reported deviations from exponential decay. Copyright (C) EPLA, 2016