🚀 go-pugleaf

In article <339315e4.391691@netnews.worldnet.att.net>
ajain1@worldnet.att.net (Rahul Jain) writes:

> On Sun, 1 Jun 1997 22:03:29 GMT, johanw@vulcan.xs4all.nl 
> (Johan Wevers) wrote:
>
> >Thomas Buckler <t.buckler@virgin.net> wrote:
> >>NEUTRINO's - What exactly is one, and how is it related to beta decay?
> >
> >They are probably (rest)massless, uncharged particles.
>
> I think the latest figure on their rest mass was less that 10^-40 or
> something ridiculously small like that.

You're thinking of photons. The current upper-limit on the mass of the
electron-neutrino is only a modest fraction of an eV. 

For a mu-neutrino, IIRC the upper-bound is several keV, and for the
tau-neutrino it's several MeV.

You can probably find the precise limits in the ``Review of Particle
Properties'' annually published by the APS (American Physical Society).


--  Gordon D. Pusch   <pusch@mcs.anl.gov>

Disclaimer:  I'm a consultant collaborating with Argonne researchers;
I don't speak for ANL or the DOE --- and they *certainly* don't speak
for =ME= !!!