Towards a Precision Measurement of Theta13 with Reactor Neutrinos

Towards a Precision Measurement of Theta13 with Reactor Neutrinos PDF Author:
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Languages : en
Pages : 5

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Book Description
Recent experimental results have provided unambiguous evidence that neutrinos have a small but finite mass and mix from one type into another. The phenomenon of neutrino mixing is characterized by the coupling between the neutrino flavor (nu e, mu, tau) and mass eigenstates (nu 1,2,3) and the associated mixing angles. Previous neutrino oscillation experiments have determined two of the three mixing angles in the neutrino mixing matrix, U MNSP. Using multiple neutrino detectors placed at different distances from a nuclear power plant, a future reactor neutrino experiment has the potential to discover and measure the coupling of the electron neutrino flavor to the third mass eigenstate, Ue3, the last undetermined element of the neutrino mixing matrix. In this paper we describe recent efforts in the US towards a next-generation experiment to measure theta13 with reactor neutrinos.

Towards a Precision Measurement of Theta13 with Reactor Neutrinos

Towards a Precision Measurement of Theta13 with Reactor Neutrinos PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
Recent experimental results have provided unambiguous evidence that neutrinos have a small but finite mass and mix from one type into another. The phenomenon of neutrino mixing is characterized by the coupling between the neutrino flavor (nu e, mu, tau) and mass eigenstates (nu 1,2,3) and the associated mixing angles. Previous neutrino oscillation experiments have determined two of the three mixing angles in the neutrino mixing matrix, U MNSP. Using multiple neutrino detectors placed at different distances from a nuclear power plant, a future reactor neutrino experiment has the potential to discover and measure the coupling of the electron neutrino flavor to the third mass eigenstate, Ue3, the last undetermined element of the neutrino mixing matrix. In this paper we describe recent efforts in the US towards a next-generation experiment to measure theta13 with reactor neutrinos.

Measurement of Theta13 with Reactor Neutrinos

Measurement of Theta13 with Reactor Neutrinos PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
Recent experimental results have provided unambiguous evidence that neutrinos have a small but finite mass and mix from one type into another. The phenomenon of neutrino mixing is characterized by the coupling between the neutrino flavor (nu{sub e, mu, tau}) and mass eigenstates (nu{sub 1,2,3}) and the associated mixing angles. Previous neutrino oscillation experiments have determined two of the three mixing angles in the neutrino mixing matrix, U{sub MNSP}. Using multiple neutrino detectors placed at different distances from a nuclear power plant, a future reactor neutrino experiment has the potential to discover and measure the coupling of the electron neutrino flavor to the third mass eigenstate, U{sub e3}, the last undetermined element of the neutrino mixing matrix.

Independent Measurement of the Neutrino Mixing Angle [theta]13 Via Neutron Capture on Hydrogen at Daya Bay

Independent Measurement of the Neutrino Mixing Angle [theta]13 Via Neutron Capture on Hydrogen at Daya Bay PDF Author:
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Languages : en
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A new measurement of the [theta]13 mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of the [theta]13 measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GWth reactors, the rate deficit observed at the far hall is interpreted as sin22[theta]13=0.083"0.018 in the three-flavor oscillation model. When combined with the gadolinium-capture result from Daya Bay, we obtain sin22[theta]13=0.089"0.008 as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.

Measurement of Neutrino Mixing Angle Θ13 in the Daya Bay Reactor Neutrino Experiment

Measurement of Neutrino Mixing Angle Θ13 in the Daya Bay Reactor Neutrino Experiment PDF Author:
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Languages : en
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Measurement of Theta-13 Neutrino Mixing Angle from the Disappearance of Electron Antineutrinos at the Double Chooz Experiment

Measurement of Theta-13 Neutrino Mixing Angle from the Disappearance of Electron Antineutrinos at the Double Chooz Experiment PDF Author: Brandon Reed White
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Languages : en
Pages : 168

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The measurement of the remaining neutrino-mixing angle, [theta]13, is a critical step toward further understanding of neutrino properties and to guide future neutrino oscillation experiments. Double Chooz has a unique opportunity to perform this measurement building on the original CHOOZ reactor anti-neutrino experiment, the experience that set the previous limits on [theta]13. In the first phase of Double Chooz, 101 days of data was analyzed with only the far detector operating of a two-detector plan. In this thesis I will describe the design of the low background neutrino detector and the oscillation analysis performed. From the deficiency between the expected and measured number of electron anti-neutrinos a value of sin2(2[theta]13) = 0.104 ± 0.03(stat) ± 0.076(syst) was found for rate only analysis and 0.086 ± 0.041(stat) ± 0.030(syst) with the rate and spectral energy shape analysis.

The Future of Reactor Neutrino Experiments

The Future of Reactor Neutrino Experiments PDF Author: Kam-Biu Luk
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Languages : en
Pages : 5

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Results from non-accelerator neutrino oscillation experiments have provided evidence for the oscillation of massive neutrinos. The subdominant oscillation, the coupling of the electron neutrino flavor to the third mass eigenstate, has not been measured yet. The size of this coupling U{sub e3} and its corresponding mixing angle theta{sub 13} are critical for CP violation searches in the lepton sector and will define the future of accelerator neutrino physics. The current best limit on U{sub e3} comes from the CHOOZ reactor neutrino disappearance experiment. In this talk we review proposals for future measurements of theta-13 with reactor antineutrinos.

New Measurement of [theta]13 Via Neutron Capture on Hydrogen at Daya Bay

New Measurement of [theta]13 Via Neutron Capture on Hydrogen at Daya Bay PDF Author:
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Languages : en
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This article reports an improved independent measurement of neutrino mixing angle [theta]13 at the Daya Bay Reactor Neutrino Experiment. Electron antineutrinos were identified by inverse [beta]-decays with the emitted neutron captured by hydrogen, yielding a data set with principally distinct uncertainties from that with neutrons captured by gadolinium. With the final two of eight antineutrino detectors installed, this study used 621 days of data including the previously reported 217-day data set with six detectors. The dominant statistical uncertainty was reduced by 49%. Intensive studies of the cosmogenic muon-induced 9Li and fast neutron backgrounds and the neutron-capture energy selection efficiency, resulted in a reduction of the systematic uncertainty by 26%. The deficit in the detected number of antineutrinos at the far detectors relative to the expected number based on the near detectors yielded sin22[theta]13 = 0.071 ± 0.011 in the three-neutrino-oscillation framework. As a result, the combination of this result with the gadolinium-capture result is also reported.

Double Chooz and a History of Reactor [theta]13 Experiments

Double Chooz and a History of Reactor [theta]13 Experiments PDF Author:
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Category :
Languages : en
Pages : 20

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This is a contribution paper from the Double Chooz (DC) experiment to the special issue of Nuclear Physics B on the topics of neutrino oscillations, celebrating the recent Nobel prize to Profs. T. Kajita and A.B. McDonald. DC is a reactor neutrino experiment which measures the last neutrino mixing angle [theta]13. In addition, the DC group presented an indication of disappearance of the reactor neutrinos at a baseline of similar to 1 km for the first time in 2011 and is improving the measurement of [theta]13. DC is a pioneering experiment of this research field. In accordance with the nature of this special issue, physics and history of the reactor-[theta]13 experiments, as well as the Double Chooz experiment and its neutrino oscillation analyses, are reviewed.

Measuring Theta_13 at Daya Bay

Measuring Theta_13 at Daya Bay PDF Author:
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Languages : en
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We measured the neutrino mixing angle, theta13, presumably related to the preponderance of matter over antimatter in our universe with high precision. We determined theta13 by measuring the disappearance of neutrinos from a group of six nuclear reactors. The target, located inside a mountain at about 2 km from the reactors, is 80 tons of liquid scintillator doped with trace amount of Gadolinium to increase its neutron detection efficiency. The neutrino flux is measured by the inverse beta-decay reaction where the final-state particles are detected by the liquid scintillator. The measured value of theta13, based on data collected over 3 years, is large, around 8 degrees, rendering the measurement of the parameter related to matter-antimatter asymmetry in future long baseline neutrino experiments easier.

Estimating the Neutron Background Toward the Measurement of Neutrino Mixing Angle [theta]13 with the Double Chooz Detector

Estimating the Neutron Background Toward the Measurement of Neutrino Mixing Angle [theta]13 with the Double Chooz Detector PDF Author: Deepak Shrestha
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Languages : en
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Double Chooz is a reactor neutrino experiment which has shown evidence of electron anti-neutrino disappearance at 1 km distance. It has been able to exclude the no-oscillation hypothesis at 99.8% CL (2.9[sigma]) with only one detector. From a rate plus spectral shape analysis, the value of sin22[theta]13 was found to be 0.109 ± 0.030(stat) ± 0.025(syst). Correlated events mimicking an anti-neutrino event are one of the most important backgrounds for a reactor neutrino experiment like Double Chooz which measured the neutrino mixing angle [theta]13. Cosmic muons passing through the rock surrounding the detector produce fast neutrons which give rise to correlated events through proton recoil followed by a neutron capture. Muons stopping around the chimney region subsequently decay into Michel electrons also contributing to the correlated background. Measurement of the shape and rate of this background is very important for the precise measurement of [theta]13. Experimental techniques to estimate of the shape and rate of this background in the Double Chooz far detector are presented in this thesis.