Post-exponential decay

Enhancing Post-Exponential Decay via Distant Detectors 520... 

Transition from exponential to post-exponential decay 524... 

Abstract We review the post-exponential decay regime in quantum mechanics, with... 

Before launching into a discussion of post-exponential decay, it is useful to understand why exponential decay should be the norm in a quantum system, even though sometimes it holds over a limited time interval, or only approximately. The Gamow and Weisskopf-Wigner theories provide a clue. 

The above results, developing the classical model suggested by Newton so as to achieve an accurate match between classical and quantum decays, provide an intuitive physical picture and quantitative description of post-exponential decay of the probability density at points distant from the source. Note that quantum mechanics is required to provide the emission characteristics, but ISR plays no role in the classical, purely outgoing dynamics. We have checked with the methodology of [58] that ISR... 

He ls2p core-excited shape resonance, with time-dependent methods. The post-exponential decay occurs in that case after 12 lifetimes. 

ENHANCING POST-EXPONENTIAL DECAY VIA DISTANT DETECTORS... 

In the present section we discuss a quite different strategy with the important advantage of simple implementation. We show, using solvable decay models, that by increasing the distance of the observation point from the source, the transition from exponential to post-exponential decay occurs at higher probability densities and thus becomes more easily observable. Finally, note that when the distance is too large the exponential decay regime... 

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