Noncharacteristic half-lives in radioactive decay

Noncharacteristic half-lives in radioactive decay.

Half-lives of radionuclides span more than 50 orders of magnitude. We characterize the probability distribution of this broad-range data set at the same time that we explore a method for fitting power laws and testing goodness-of-fit. It is found that the procedure proposed recently by Clauset et al. [SIAM Rev. 51, 661 (2009)] does not perform well as it rejects the power-law hypothesis even fo...

Simple relation for alpha decay half-lives.

The experimental values of log&pT, yp(sec) plotted vs Zz /QQ are shown to fall on a nearly universal straight line with log, oT, ~z(sec)=(9. 54Z~. /1/Q ) —51.37, where Zz is the charge number of the daughter nucleus and Q is expressed in units of MeV. This behavior also numerically comes out of the semiclassical WKB calculation of the barrier penetration factor. The fine structure in the ratio ...

Do radioactive half-lives vary with the Earth-to-Sun distance?

Recently, Jenkins, Fischbach and collaborators have claimed evidence that radionuclide half-lives vary systematically over a ±0.1% range as a function of the oscillating distance between the Earth and the Sun, based on multi-year activity measurements. We have avoided the time-dependent instabilities to which such measurements are susceptible by directly measuring the half-life of (198)Au (t(1/...

Test of claims that radioactive half-lives depend on the Earth-Sun distance

β-decay half-lives of heavy neutron-rich nuclei in the N≈126 region

The astrophysical r-process is responsible for the synthesis of approximately half of the heavy nuclei in the Universe. One of the main problems we have to overcome to fully understand the observed r-process abundances is the lack of information on the nuclei participating in this process, in particular for the heaviest ones. The production of heavy neutron-rich nuclei in the laboratory has bee...