Center for Theoretical Physics of the Universe (CTPU)
New results from RENO and future project RENO-50
by Prof. Sunny Seo (SNU)
Wednesday, 15 June 2016 from to (Asia/Seoul)
RENO (Reactor Experiment for Neutrino Oscillation) is designed to measure the neutrino mixing angle theta_13 and the effective mass squared difference |dm^2_ee| using electron anti-neutrinos from six reactors at Hanbit nuclear power plant in S. Korea. RENO has been taking data since August 2011 using two identical detectors at near and far sites. The unprecedented measurement of the theta_13 by RENO was made in 2012 with 4.9 sigma significance using 220 live days of data. In this talk we present the updated sin^2(2q13) value and first measurement on |dm^2_ee| based on a spectral shape analysis using 500 live days of data. And they are sin^2 (2theta_13) = 0.082 +- 0.009(stat.) +- 0.006 (syst.) and |dm^2_ee| = 2.62 +0.21 -0.23 (stat.) +0.12 -0.13(syst.) (X 10^-3 eV^2. The systematic uncertainty of sin^2(2q13) has improved mainly due to the better estimation of the Li9/He8 background and the reduction of its uncertainty. The update on the 5 MeV excess of the electron anti-neutrino events and the R&D status of RENO-50 are also discussed.