From: sichase@csa2.lbl.gov (SCOTT I CHASE)
Newsgroups: sci.physics
Subject: Re: Vector Bosons?
Date: 13 Aug 92 20:10:28 GMT
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
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In article <1992Aug13.172944.8730@asl.dl.nec.com>, terry@aslws01.asl.dl.nec.com (Terry Bollinger) writes...
> 
>BOSONS
> 
>For whatever it's worth, a boson is simply a particle with integral spin
>(spin = {..,-2,-1,0,1,2,..} ), and fermions are particles whose spins
>contain half-unit (spin = { -1 1/2, -1/2, +1/2, +1 1/2 } ).  The idea of

There is no such thing as negative spin.  A particle with total positive
spin S can have a negative component along any given axis, however, which 
probably lead you to this confusion. 

>In all observed cases, bosons states are "commutative" -- meaning more-or-
>less that when all the math has been said and done, bosons really like to
>be in the same spot at the same time, doing the same thing.  Moreover, the
>bigger the party is (that is, the larger the number of bosons "doing the
>same thing" becomes -- see Feynman III for details), the more attractive
>that "state" becomes to other bosons of that type.  Bosons thus are a most
>gregarious bunch, true party animals -- except that their parties tend
>towards the dull side, what with *everyone* doing exactly the same thing.

How about, "what with *everyone* doing more or less the same thing."?  
Except at zero temperature, the particles in a bose condensate are *not*
all in the same energy level.

>In quantum field theory, the gregarious (commutative) behavior of bosons
>leads to another interesting effect.  It implies that "virtual" bosons
>become the mediators of the various forces that hold things together --
>e.g., virtual photons mediate the electromagnetic force, virtual W
>particles help mediate the weak force, and gluons mediate the strong
>force between quarks.

There is nothing about the statistical properties of bosons which 
implies that they should be the mediators of the various forces.  There
is no cause and effect here.  There are fundamental bosons, such as the
Higgs or axion, which may exist but are not intermediate bosons.

>Having fermions around is a major factor in why you, the reader, are not
>currently part of a little grape-sized black hole orbiting where the earth
>used to be.  Fermions in general and atomic electrons (spin 1/2 fermions)
>in particular will strongly resist any compression beyond a certain point,
>making the volume-occupying properties of ordinary matter possible.

It is the electric charge of the electron, not its spin, which is primarily
responsible for the volume of matter.  If the electron were a boson, then
all atoms would have the radius of a hydrogen atom.  That certainly would
shrink things a bit, but not enough to collapse the Earth into a grape-sized
black hole.   Only if the electric charge of the electron were turned off,
as it effectively is inside a neutron star, where electrons and protons have
combined to produce electrically neutral neutrons, do things get really
dense.

> 
>				Cheers & hows that for overkill,
>				Terry Bollinger

Well done, except for the few nits picked above.

-Scott
--------------------
Scott I. Chase			"The question seems to be of such a character
SICHASE@CSA2.LBL.GOV		that if I should come to life after my death
				and some mathematician were to tell me that it
				had been definitely settled, I think I would
				immediately drop dead again."      - Vandiver