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

- 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 Z^{0} is quite massive, 91.2 Gev/c^{2}. 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)*