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Re: [Phys-L] [Phys-l] Question about Quarks and the Standard Model



I think this may be relevant?

Advances in Optics and Photonics, Vol. 3 Issue 2, pp.161-204 (2011)
Yao, Alison M; Padgett, Miles J

As they travel through space, some light beams rotate. Such light beams have angular momentum. There are two particularly important ways in which a light beam can rotate: if every polarization vector rotates, the light has spin; if the phase structure rotates, the light has orbital...


bc

On 2008, Dec 14, , at 08:07, John Denker <jsd@av8n.com> wrote:

On 12/14/2008 06:57 AM, chuck britton wrote:

No, the coulomb force does not come from the "exchange of gauge
bosons (the photon)". Photons exert only transverse forces; the
coulomb
force is longitudinal.

hmmm, never put these two facts together.
I'll have to rank this right up there as a major misconception.
gotta pull out those Feynman Lectures.
but just a word or two before I locate the books - would be
appreciated.

Don't panic.

Non-virtual photons are required to be transversely polarized.
Virtual ones have no such requirement.

This is a contrast between virtual and non-virtual, but it
is not a contradiction or a paradox.

By way of example, the following paper explicitly separates
the longitudinal and transverse polarizations of the virtual
photon:
http://arxiv1.library.cornell.edu/pdf/hep-ph/9910370v1

This is apparently not much discussed in textbooks; most
people take it as obvious from experience that the Coulomb
interaction is longitudinal.

My guess is that to make progress, you need to look at the
"proof" that photons are (allegedly) necessarily transverse,
and understand why it doesn't apply to virtual photons.

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