What is the range of the interaction R, in nuclear physics?

$R=c\Delta t$

where $t$ is the time interval in which some virtual particle is exchanged.

Or, for beta decay, the range of the intercation is given by:


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1 Answer 1


You just wrote down the range of interaction:

$$ R = \frac{\hbar}{mc} = \frac{\hbar c}{mc^2}$$

Note that all nuclear physicists know:

$$\hbar c = 197\, {\rm Mev\cdot fm} $$

and have memorized all the masses of the light mesons, so:

$$ R = \frac{197\, {\rm Mev\cdot fm}}{m_{\pi}c^2} = \frac{197\, {\rm Mev\cdot fm}}{140{\,\rm MeV}} \approx 1.4\,{\rm fm}$$

which is comparable to the proton size.

Regarding propagation times of virtual particles...that's not really a fruitful line of thinking.


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