South Pole Telescope Data Places Better Limit on Neutrino Mass

An anonymous reader writes an excerpt from a press release by the University of Chicago: "Analysis of data from the 10-meter South Pole Telescope is providing new support for the most widely accepted explanation of dark energy — the source of the mysterious force that is responsible for the accelerating expansion of the universe." The research resulted in three papers involving new constraints on the mass of neutrinos, a measurement of the angular power spectrum of the CMB, and a catalog of newly discovered galaxy clusters. The data lends a bit more support to the cosmological constant theory of dark energy.

Comments

Neutronio

[GameboyRMH]

It's-a me, Neutronio!

lower limit on neutrino mass?

[snoop.daub]

The experiment reports a new upper limit on the neutrino mass. I've seen upper limit estimates before this one, but I don't ever recall seeing a lower limit reported on a direct measurement of the neutrino mass. Nonzero mass is a requirement in standard theories of neutrino oscillation but that's a consequence of the theory, not a direct measurement. Is there a direct measurement of a lower limit out there that I'm not aware of?

Re:lower limit on neutrino mass?

[Anonymous Coward]

There are measurements that can determine the difference in the neutrino masses, or some similar function (e.g. difference in their masses squared). This gives that at least one of the neutrinos has a mass of 0.04 eV, and a second one has to have a mass of at least 0.009 eV. It doesn't really give a lower bound on the smallest one, although there are some other estimates of their masses from cosmological and astronomical data.