Re: A question about the spin 2 particle.

[Jack Uretsky <jlu@HEP.ANL.GOV>]

I am always troubled by questions involving "someone told me that".  Also,
I don't understand what the purported quote has to do with the rest of the
question.
                                Regards,
                                        Jack
On Mon, 25 Dec 2000, Robert B Zannelli wrote:

> In a message dated 12/25/00 12:52:51 PM Eastern Standard Time,
> jlu@HEP.ANL.GOV writes:
>
> << His question appears to be based upon an out-of-context quote of
>  language from Adair.  Adair, a fine physicist and talented writer, has
>  chosen for reasons of his own to invent the term "DeBroglie amplitude".
>  In order to understand the term, and the reason for inventing it, one must
>  read Adair, which I (and perhaps many others) have not.  Zannelli
>  couples Adair's language with (apparently) a
>  recollection, of uncertain accuracy, of something Feynman wrote, which I
>  also have not seen. >>
>
> Perhaps what you say is correct. Let me try to clearly express what my
> question is and if the my question is off base then someone could tell me.
> When a fermion particle is rotated in space than two complete rotations are
> required to restore it's probability amplitude to it's original sign. A
> single rotation returns the negative of the original amplitude. For a vector
> particle a single rotation returns the same amplitude.
> It would seem to follow that for a spin 2 particle a one pi rotation would
> return the same amplitude.
>    Now during a discussion on another physics list someone made the point
> that Feynman had proven that a two pi rotation is equivalent to a particle
> exchange. Of course if this is true it doesn't negate the possibility that a
> spin 2 particle returns the same probability amplitude after a one pi
> rotation.
>     The consensus on the other list, which I received before receiving the
> first response from this list, was that the for a spin 2 particle the
> probability amplitude is returned after a one pi rotation.
>      One of the reasons for this question is, that if true, one can develop
> an interesting analogy between particle spin and closed 2 space manifolds
> embedded in a three space. But that's another story.
>
> Bob Zannelli

--
While [Jane] Austen's majestic use of language is surely diminished in its
translation to English, it is hoped that the following translation conveys
at least a sense of her exquisite command of her native tongue.
                        Greg Nagan from "Sense and Sensibility" in
                     <The 5-MINUTE ILIAD and Other Classics>