forbidden transitions

[Kjell Johansen <kjell.johansen@wepco.com>]

John Jacobus inquired about forbidden transitions during beta decay.

Beta decays are either "allowed" or "forbidden" nuclear transitions.  A
beta decay in which spin and parity of the nucleus remain unchanged are
called allowed transitions.  Decays in which spin and/or parity changes
occur are called forbidden transitions.  In the former case a rather
large decay constant is implied; in the latter, only a small decay
constant.  In general there is an inverse relationship between the decay
constant and the degree of "fobiddenness."  Spin and parity are quantum
mechanical properties of atoms.

You should be able to get further info on this in Evans' The Atomic
Nucleus.  My description above is from Fitzgerald, Brownell, and
Mahoney, Mathematical Theory of Radiation Dosimetry, 1967, Gordon and
Breach, which, I believe, is long out of print.  You may also find
something in Radiation Dosimetry by Hine and Brownell.

Kjell.Johansen@wepco.com
Kjell Johansen
Wisconsin Electric
Milwaukee, WI
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