New Daya Bay Results
Physics conferences are providing new measurements for neutrino oscillation parameters (in the case of the Daya Bay measurements the precision of the measurement sets a new record).
Via Physics Forums (hurray for Twitter which announced data not found in the press release from Daya Bay or at arXiv).
Prior to these results the global average Particle Data Group (PDG) results were as follows:
Translated into raw values of the parameters themselves, the best fit Daya Bay theta13 value is 8.49º compared to a PDG value of 8.53º. These results are consistent at the one sigma level. (The PDG value of theta12 is 33.65º.)
The square root of the normal hierarchy Δm232 is 49.5 meV (while it is 49.1 meV for the NOvA measurement below). The PDG value is 49.53 meV. The two measurements and the world average are all consistent with each other within their uncertainties. (The PDG delta m12 value is 8.68 meV.)
The Daya Bay presentation also included the following summary of results from other experiments:
New NOvA Collaboration Results
There are also new results from the NOvA collaboration:
The best-fit values for the atmospheric parameters are
eV , and .
The data disfavor combinations of oscillation parameters that lead to large asymmetries between the rates of νe vs ν¯e appearance.
- θ12 = 13.04±0.05°,
- θ13 = 0.201±0.011°,
- θ23 = 2.38±0.06°
- δ13 = 1.20±0.08 radians = 68.8±4.5°.