New measurement of antineutrino oscillation with the full detector configuration at Daya Bay.
نویسندگان
چکیده
We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×10^{5} GW_{th} ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six ^{241}Am-^{13}C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin^{2}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3} eV^{2} in the three-neutrino framework.
منابع مشابه
Assembly and Installation of the Daya Bay Antineutrino Detectors
The Daya Bay reactor antineutrino experiment is designed to make a precision measurement of the neutrino mixing angle θ13, and recently made the definitive discovery of its nonzero value. It utilizes a set of eight, functionally identical antineutrino detectors to measure the reactor flux and spectrum at baselines of ∼ 300 2000m from the Daya Bay and Ling Ao Nuclear Power Plants. The Daya Bay a...
متن کاملDaya Bay Neutrino Experiment
The observation of neutrino oscillation in experiments involving solar, atmospheric, accelerator, and reactor neutrinos has demonstrated that the masses of neutrinos are nonzero, and neutrinos with different flavors can mix with each other to form the mass eigenstates. Neutrino oscillation has provided the only compelling evidence thus far for new physics beyond the standard model (SM). The sma...
متن کاملA Study of Systematic Uncertainties in the Daya Bay Neutrino Experiment using the GLoBES Software
The Daya Bay reactor neutrino experiment is designed to set a precision upper limit on, if not pin-point, the value of the θ13 neutrino oscillation parameter. As shown in the parameterized Pontecorvo-Maki-Nakagawa-Sakata matrix, accurate measurement of θ13 may enable the study of CP violation in the lepton sector, in addition to supporting our understanding of neutrino oscillation arising from ...
متن کاملSearch for sterile neutrinos with a radioactive source at Daya Bay
The far site detector complex of the Daya Bay reactor experiment is proposed as a location to search for sterile neutrinos with eV mass. Antineutrinos from a 500 kCi Ce-Pr -decay source ( Q 1⁄4 2:996 MeV) would be detected by four identical 20-ton antineutrino targets. The site layout allows flexible source placement; several specific source locations are discussed. In one year, the 3þ 1 steril...
متن کامل(Non)decoherence in the Daya Bay Reactor Antineutrino Experiment
The topic of decoherence in neutrino oscillations is intellectually interesting, but it is not relevant to a successful neutrino-oscillation experiment such as Daya Bay, in that if oscillations were observed, then there was essentially no decoherence in the experiment. As such, little knowledge of decoherence can be extracted from the data of a successful neutrino experiment, and a discussion o...
متن کاملReactor antineutrino anomaly with known 13
We revisit the reactor antineutrino anomaly using the recent reactor flux independent determination of sizable 13 by considering the full set of the absolute reactor e flux measurements. When normalized to the predicted flux of Mueller et al. [Phys. Rev. C 83, 054615 (2011)], the new world average, after including results from Palo Verde, Chooz, and Double Chooz, is 0:959 0:009 (experiment unce...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 115 11 شماره
صفحات -
تاریخ انتشار 2015