Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment.
The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3}  eV^{2}.
Department of Radiology, Dongshin University, Naju 58245, Korea.
J H
JH
Choi
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
W Q
WQ
Choi
Department of Physics, Sungkyunkwan University, Suwon 16419, Korea.
Y
Y
Choi
Department of Fire Safety, Seoyeong University, Gwangju 61268, Korea.
H I
HI
Jang
GIST College, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
J S
JS
Jang
Institute for Basic Science, Daejeon 34047, Korea.|Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea.
E J
EJ
Jeon
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
K K
KK
Joo
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
B R
BR
Kim
Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea.
H S
HS
Kim
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
J Y
JY
Kim
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
S B
SB
Kim
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
S Y
SY
Kim
Department of Physics, Kyungpook National University, Daegu 41566, Korea.
W
W
Kim
Institute for Basic Science, Daejeon 34047, Korea.|Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea.
Y D
YD
Kim
Department of Physics, Chung Ang University, Seoul 06974, Korea.
Y
Y
Ko
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
D H
DH
Lee
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
I T
IT
Lim
Department of Radiology, Dongshin University, Naju 58245, Korea.
M Y
MY
Pac
Department of Physics, Gyeongsang National University, Jinju 52828, Korea.
I G
IG
Park
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
J S
JS
Park
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
R G
RG
Park
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
H
H
Seo
Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
S H
SH
Seo
Department of Physics, Kyungpook National University, Daegu 41566, Korea.
Y G
YG
Seon
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
C D
CD
Shin
Department of Physics, Chung Ang University, Seoul 06974, Korea.
K
K
Siyeon
Department of Physics, Sungkyunkwan University, Suwon 16419, Korea.
J H
JH
Yang
Institute for Universe and Elementary Particles, Chonnam National University, Gwangju 61186, Korea.
I S
IS
Yeo
Department of Physics, Sungkyunkwan University, Suwon 16419, Korea.
I
I
Yu