PMNS Theta 13

The parameter theta 13 in the PMNS matrix appears to be non-zero according to the latest reactor data.

A lot of modeling of neutrino oscillations assumes this is zero, since it is very small, but a non-zero value would be more consistent with quark-lepton complementarity, because that would not be a match to the corresponding angle in the CKM matrix is off by about two tenths of a degree from the value that would suggest a zero value for theta 13 in the PMNS matrix. The prediction from quark-lepton complementarity (as of 2007 from the CKM matrix figures known at that time) would be a theta13 of 8-10 degrees. This result implies a theta13 of 8.5 degrees (working my way back from sine squared two theta equal to 0.085).

More at Resonaances poking fun at the low level of statistical significance involved while not dismissing out of hand the result which in line with other experimental measurements and is plausible from a theoretical point of view.