Re: Decaytimes of Leptons

Josef Matz wrote: 
I just want to ask if the Standard - Model of Leptons has a theory for the
decay times of the Myon and the Tau.

The SM *is* the theory you ask for, and yes, it provides a way to calculate the decay amplitude for the heavy leptons. The leading-order scattering amplitude \mu -> something will give you quite precise numbers.

What Environment Parameters (Bonding in an Atom, Temperature etc. )
influence the decay ?

Everything you can take in account will probably alter the result in some way, although muons are usually produced as quasi-free particles.
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