Re: Binary stars

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

One small correction to John's list.  But I have a deeper objection
to Ludwik's characterization (see next msg)

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run downhill,
not up.
                          Mark Twain, <Extract from Eve's Autobiography>

On Sat, 18 Dec 1999, John S. Denker wrote:

> At 10:59 AM 12/18/99 -0500, Ludwik Kowalski wrote:
>
> > proton and antiproton. To have
> > them circle about the common C.M.  Was a
> > proton-antiproton "binary star" ever observed experimentally?
>
> Sure.  Just shoot antiprotons at hydrogen.
>
> > Should it be called a heavy neutron
>
> No.
>
> > or a hydrogen "atom"?
>
> Sometimes it is called that, but I'm not convinced it's the optimal name.
>
> -------------
>
> Other critters of interest include:
>
> Positronium:    an electron orbiting a positron (or vice versa :-).  It's
> more stable than you might think, and provides elegant and sensitive tests
> of quantum electrodynamics.
>
> Muonium:  an electron orbiting a mu+.

        I think that current usage is a mu+ mu- atom.  In that usage,
quark + anti-quark states (like the J/psi and the Upsilon) are referred
to generically as quarkonium.
> Muonic atoms:  An atom where one of the electrons has been replaced by a
> mu-.  Especially in the case where it is one of the 1s electrons that gets
> replaced, the muon spends a lot of time overlapping the nucleus, thereby
> providing useful information about nuclear structure.