[Dan1195]

I was looking at some of the decay chains of the ²⁷⁷112->²⁶⁵Sg series as well as for ²⁸⁷114 and was wondering how does it get determined if an SF termination of a decay chain is from nuclide X or its daughter Y (with the alpha decay of X missing) in the case where daughter lifetime is less than that of the parent.

The GSI ²⁸³112 data shows a significant SF branch. None of the Dubna data shows this. They do however have have 4 chains with long SF lifetimes all assigned to ²⁷⁹Ds following a missed alpha.

In ²⁶⁵Sg (state populated from ²⁶⁹Hs as opposed to direct production) also has 4 cases where an alpha was apparently missed and relatively long SF was assigned to the SF decaying isomer of ²⁶¹Rf. I bring up ²⁶⁵Sg because No SF branch has been measured here. But SF systematics for odd Neutron Sg isotopes would indicate a partial SF half-life of between 30-105 seconds (partial SF half lives for ^261,267Sg which should have been detected with the number of atoms observed.

Would seem best things one would have to go on is the expectation of number of missed alphas based on detector efficiency.

[gippgig]

There is no way to be certain of this and if only a single decay chain is observed this is a very real possibility (i.e., ²⁸⁷115). The more decay chains that are observed without an alpha the less likely this becomes. Some papers (don't remember which offhand) have given estimates of how likely this is to have occurred.