Combining Accelerator and Reactor Measurements of theta_13; The First Result

TL;DR

This paper reports the first combined measurement of the neutrino mixing angle theta_13 using data from multiple reactor and accelerator experiments, confirming a non-zero value with high significance.

Contribution

It presents the first combined analysis of reactor and accelerator data to measure theta_13, achieving a precise determination and rejecting the zero hypothesis at 7.7 sigma.

Findings

sin^2 2theta_13 = 0.096 1.013 (0.040) at 1 sigma (3 sigma) CL

theta_13 = 0 is rejected at 7.7 sigma significance

Future data will improve the precision of theta_13 measurement.

Abstract

The lepton mixing angle theta_13, the only unknown angle in the standard three-flavor neutrino mixing scheme, is finally measured by the recent reactor and accelerator neutrino experiments. We perform a combined analysis of the data coming from T2K, MINOS, Double Chooz, Daya Bay and RENO experiments and find sin^2 2theta_13 = 0.096 \pm 0.013 (\pm 0.040) at 1 sigma (3 sigma) CL and that the hypothesis theta_13 = 0 is now rejected at a significance level of 7.7 sigma. We also discuss the near future expectation on the precision of the theta_13 determination by using expected data from these ongoing experiments.