Thanks Wesley. Let me try to rephrase my question. I bungled it last time.
Suppose we have a qubit whose state over time is given by:
Psi(t) = sin(t) |0> + cos(t) |1>
(Not that I have any idea if such a thing exists in reality). Then quick successive measurements will leave the particle in state |1>.
How does this look for radioactive decay (thanks for pointing out it was radioactive decay, btw)? I suppose I could think of |1> as un-decayed and |0> as decayed, and then the time evolution is simply the usual exponential decay function. I'm just trying to frame QZE for decay in a familiar way (like the qubit example).
[Actually, I just came upon this blog post which may explain it: http://carlbrannen.wordpress.com/200...dox-or-effect/
[edit: btw, one thing that was confusing me was talk of the particle's state
decaying. I wasn't sure if this was something different from its state evolving