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Q & A: Range of forces in particle physics

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Most recent answer: 07/30/2013
Q:
is it correct to state that the necessary conditions for having an infinite-range interaction are that the quanta associated to the field, i.e., the gauge bosons are 1)massless and 2)chargeless (in the sense of the charge associated to that particular field)?
- Mateo (age 22)
Madrid, Spain
A:

By 'infinite-range interaction' I presume that you mean the effective potential falls off as  1/r.   Two good examples are the Coulomb and  gravitational potentials.   Both have zero mass gauge particles and zero charge, the photon and the graviton.  An example of a short range force that has non-zero mass gauge particle is that of the weak interaction where  the neutral gauge boson, the Z0 is quite massive, 91.2 Gev/c2.  The 'Yukawa' potential which was developed to explain the short range of nuclear forces goes as  V(r) ~ e-km/r/r  where m is the pion mass. So the smaller the mass, the larger the range.

There is probably a much deeper field theoritic reason for this but I don't know it.   I'll have to ask one of my local experts.

 

LeeH


(published on 07/30/2013)

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