Re: Question About Charged Particles.

["John S. Denker" <jsd@MONMOUTH.COM>]

At 08:43 AM 4/8/01 -0500, Jack Uretsky wrote:
>  I never said that the question is trivial - I said that
> it strikes me as a non-question because the answer depends upon the model
> that one chooses.

OK, the answer to this question is model-dependent.

Now, is that the only objection to the question?
 -- If that is not the only objection, would somebody please clarify what
the other objections might be?
 -- If that is the only objection, then the converse of Jack's statement
must apply:  If we knew what model to choose, then the alleged
"non-question" would suddenly become a valid question.

Saying we don't know what model to choose is just a fancy way of saying we
don't know with confidence how to answer the question.  I still think we
shouldn't criticize the question just because it is hard to answer.

>         My point is that Zanelli's question can be answered either way,
> depending on what model one relies upon.  Said otherwise, to the extent
> that the question implies a model (as it did in one version), then that
> model provides an answer.

OK.

> In QCD we have the peculiar
> circumstance (in the confining phase) that the constituents cannot appear
> as asymptotic states, so the usual tools of quantum field theory seem
> not seem to make sense.

That seems to support the view that we don't know how to answer the
question with confidence.

>         John's argument is also troublesome.  If a particle is massless,
> it must be moving with the speed of light.  I don't know how to turn on a
> charge on such an object.  He argues in terms of the field that accompanies a
> charged object in its rest frame.  But once he assumes a rest frame he
> has already implied that the object is massive.

That's a sensible physical argument.  But if you read my previous note
carefully, I weaseled out of that by considering the case of something with
a very, very small but nonzero mass.  If we can imagine a charged particle
with 2000 times less mass than a proton, why can we not imagine a charged
particle with 10^25 times less mass than a proton?  Such a particle would
uphold the massless dispersion relation
        E = p c
to an excellent approximation at all temperatures that have ever been
achieved.  It's not obvious to me how one would design an experiment to
prove that such a particle is non-massless.  Maybe some smart person could
enlighten me.  CAVEAT:  I'm not saying such particles must exist.  I'm just
saying that AFAIK their non-existence has not been proved with 100%
certainty.  In the absence of such a proof, I consider them to be a
_remote_ possibility.

BTW, if they existed, one would have the burden of explaining why electrons
don't routinely decay into them, in analogy to the way muons decay into
electrons.  This is not an insurmountable burden.