Martin Brown ) writes:
On 24/11/2010 14:56, Sam Wormley wrote:
On 11/24/10 8:25 AM, Joe Snodgrass wrote:

Am I correct in my understanding that, although it was discovered in
1998 that the neutrino does indeed have mass, people still don't know
what that mass is? TIA.

Background
http://en.wikipedia.org/wiki/Neutrino

Generation 1
Electron neutrino νe 2.2 eV
Electron antineutrino νe 2.2 eV
Generation 2
Muon neutrino νμ 170 keV
Muon antineutrino νμ 170 keV
Generation 3
Tau neutrino ντ 15.5 MeV
Tau antineutrino ντ 15.5 MeV


I have to say I find it hard to reconcile the table of numbers given
above with the paper summarised in Science that put a rough bound on the
sum of the (rest) masses of the three types of neutrino at 0.28eV.

http://www.sciencedaily.com/releases...0712115104.htm

Well there's no actual inconsistency, since the numbers quoted were all upper
bounds. I think it's harder to put a limit on the mass of one species in
isolation than to estimate the total mass of all species (particle
physics vs astrophysics?).

--John Park