Search for anomalies in the decay of radioactive Mn-54

Department of Physics, Trinity College - Hartford, CT 06106, USA

^(a) mark.silverman@trincoll.edu

Received: 29 March 2016
Accepted: 20 June 2016

Abstract

Recent papers have reported that ⁵⁴Mn, which decays by electron capture (a weak nuclear interaction) with half-life ∼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 ⁵⁴Mn activity measured over a time interval of ∼3.6 half-lives. If standard nuclear physics applies, the logarithmic residuals of ⁵⁴Mn activities should form a stationary set of independent random variables whose statistics are determined solely by a constant decay rate λ and initial mean count μ. Analysis of the time-variation, autocorrelation, and power spectra of the ⁵⁴Mn logarithmic residuals agrees exquisitely with standard nuclear physics. Computer-simulated activities exhibiting periodic decay of amplitude show that anomalies would be detectable by these statistical tests for values of α as low as ∼1 part in 10⁴. This limit is about 10 times lower than reported deviations from exponential decay.