scholarly journals Analysis of the reactor antineutrino spectrum anomaly with fuel burnup

2020 ◽  
Vol 239 ◽  
pp. 02005
Author(s):  
Le Yang ◽  
Xubo Ma ◽  
Runze Zhu ◽  
Yaozhou Li ◽  
Zifeng Huang

Recently, three successful antineutrino experiments (Daya Bay, Double Chooz, and RENO) measured the neutrino mixing angle θ13; however, significant discrepancies were found, both in the absolute flux and spectral shape. Much effort has been expended investigating the possible reasons for the discrepancies. In this paper, the change of neutrino energy spectrum with burnup is analyzed from the point of view of the change of neutrino energy spectrum with burnup. An accurate method for calculating neutrino energy spectrum is proposed. The non-equilibrium correction is studied by using this method. It is found that the non-equilibrium correction contributes not only to the energy region less than 4.0 MeV, but also to the energy region greater than 4.0 MeV, with a maximum correction of about 3%.

2014 ◽  
Vol 31 ◽  
pp. 1460312 ◽  
Author(s):  
Masheng Yang ◽  
Yaping Cheng ◽  

The Daya Bay Reactor Neutrino Experiment has measured a non-zero value of the neutrino mixing angle θ13 with a significance of 7.7 standard deviations by a rate-only analysis.1 The distortion of neutrino energy spectrum carries additional oscillation information and can improve the sensitivity of θ13 as well as measure neutrino mass splitting [Formula: see text]. A rate plus shape analysis is performed and the results have been published.2 Understanding detector energy non-linearity response is crucial for the rate plus shape analysis. In this contribution, we present a brief description of energy non-linearity studies at Daya Bay.


2012 ◽  
Vol 27 (08) ◽  
pp. 1230010 ◽  
Author(s):  
C. MARIANI

In this document we will review the current status of reactor neutrino oscillation experiments and present their physics potentials for measuring the θ13 neutrino mixing angle. The neutrino mixing angle θ13 is currently a high-priority topic in the field of neutrino physics. There are currently three different reactor neutrino experiments, DOUBLE CHOOZ, DAYA BAY and RENO and a few accelerator neutrino experiments searching for neutrino oscillations induced by this angle. A description of the reactor experiments searching for a nonzero value of θ13 is given, along with a discussion of the sensitivities that these experiments can reach in the near future.


2019 ◽  
Author(s):  
Hyunkwan Seo

The smallest neutrino mixing angle \theta_{13}θ13 has been successfully measured by the disappearance of reactor antineutrinos at RENO, Daya Bay, and Double Chooz. The oscillation frequency is also measured based on energy and baseline dependent disappearance probability of reactor antineutrinos. Recent results find a variation in the observed reactor antineutrino flux as a function of the reactor fuel evolution. We report more precisely measured values of \theta_{13}θ13 and \Delta m_{ee}^2Δmee2 and results on the evolution of observed reactor antineutrino yield and spectrum.


2014 ◽  
Vol 2014 (10) ◽  
Author(s):  
Y. Abe ◽  
◽  
J. C. dos Anjos ◽  
J. C. Barriere ◽  
E. Baussan ◽  
...  

2015 ◽  
Vol 2015 (2) ◽  
Author(s):  
Y. Abe ◽  
◽  
J. C. dos Anjos ◽  
J. C. Barriere ◽  
E. Baussan ◽  
...  

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
T. Abrahão ◽  
◽  
H. Almazan ◽  
J. C. dos Anjos ◽  
S. Appel ◽  
...  

Abstract A θ13 oscillation analysis based on the observed antineutrino rates at the Double Chooz far and near detectors for different reactor power conditions is presented. This approach provides a so far unique simultaneous determination of θ13 and the total background rates without relying on any assumptions on the specific background contributions. The analysis comprises 865 days of data collected in both detectors with at least one reactor in operation. The oscillation results are enhanced by the use of 24.06 days (12.74 days) of reactor-off data in the far (near) detector. The analysis considers the $$ {\overline{\nu}}_e $$ ν ¯ e interactions up to a visible energy of 8.5 MeV, using the events at higher energies to build a cosmogenic background model considering fast-neutrons interactions and 9Li decays. The background-model-independent determination of the mixing angle yields sin2(2θ13) = 0.094 ± 0.017, being the best-fit total background rates fully consistent with the cosmogenic background model. A second oscillation analysis is also performed constraining the total background rates to the cosmogenic background estimates. While the central value is not significantly modified due to the consistency between the reactor-off data and the background estimates, the addition of the background model reduces the uncertainty on θ13 to 0.015. Along with the oscillation results, the normalization of the anti-neutrino rate is measured with a precision of 0.86%, reducing the 1.43% uncertainty associated to the expectation.


2016 ◽  
Vol 7 (2) ◽  
pp. 150-166 ◽  
Author(s):  
Péter Ván

Abstract The experimental basis and theoretical background of non-Fourier heat conduction is shortly reviewed from the point of view of non-equilibrium thermodynamics. The performance of different theories is compared in case of heat pulse experiments.


2018 ◽  
Vol 33 (32) ◽  
pp. 1850201
Author(s):  
O. M. Boyarkin ◽  
G. G. Boyarkina ◽  
D. S. Vasileuskaya

Within the left–right symmetric model (LRM) the [Formula: see text] boson decay into the channel [Formula: see text] are investigated. The branching ratios of this decay is found in the third order of the perturbation theory. The obtained expression does not equal to zero only at the existence of the neutrino mixings. This means that from the point of view of the LRM, the nonconservations of the neutral and the charged lepton flavors have the same nature. As a result, the elucidation of the decays [Formula: see text] [Formula: see text] could provide data concerned the neutrino sector structure of the LRM. The neutrino sector parameters which could be measured in that case are as follows: (i) difference of the heavy neutrino masses; (ii) heavy–heavy neutrino mixing; (iii) heavy–light neutrino mixing.


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