Speedy Neutrinos

A new paper posted to arxiv.org today presents a much improved speed estimate for the neutrino.

The paper is: https://arxiv.org/abs/1807.05621 .

Relevant blurb is: “Using the values mentioned above, we find |v − c| divided by c ~/< 4.2 × 10^-12 , which is 3 orders of magnitude and 6 orders of magnitude more stringent compared to that obtained from SN 1987A observations and laboratory measurements respectively.”

So the speed of the neutrino continues to be indistinguishable from light speed to ever-higher significance. This may be important for two reasons. Firstly, the fashionable neutrino-mixing hypothesis strictly requires that v < c. If that restriction is violated the finding would be revolutionary for physics. Secondly if v = c, then a radical new understanding of neutrinos is possible, as discussed in the piece below.

Also it can be noted that the constraints on neutrino masses have also tightened, as discussed here.

The very radical idea that neutrinos might be a form of gravitational radiation remains alive and well.