tetrahedron wrote:
Bjoern Feuerbacher wrote:
The angular momentum is the generator of rotations. Does that help in
any way?
Not really. You mean the angular momentum is what causes the
particle's own rotation?
Depends on what exactly you mean by "causes" here. This is
more about math than about physics.
I don't remember how it was in classical physics precisely,
but in QM, the operator exp(i alpha L_z/ hbar), when acting
on a wave function psi(r,theta,phi), will give you the wave function at
the point r,theta,phi+alpha.
Are we talking about this or the rotation of
the frame of reference? At any rate, even if the angular momentum is
quantized, this doesn't mean the rotations are (they have to do with
the position, while the angular momentum has to do with the rate of
change of the position).
Agreed.
[snip]
All odd-half-integer require 2 rotations
All integer spins require 1 rotation
I don't see the immediate connection between spin and "period of the
wave function" (is that what we mean by number of rotations?)
For *orbital* angular momentum, one can show that a wave function
which describes an object which has m*hbar as the z component of the
angular momentum contains a factor exp(i m phi).
Besides some mesons, I don't know of any such particle
physically observed.
Some atoms and nuclei. IIRC, the helium atom is the easiest
example.
I forgot to add "elementary" or at least subatomic.
Well, then I also don't know of any, besides some mesons.
The Higgs boson is assumed to have spin 0, but it has not
been observed so far.
Bye,
Bjoern
.
