scholarly journals Neutrino Oscillation Analysis of 217 Live Days of Daya Bay and 500 Live Days of RENO

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Mario A. Acero ◽  
Alexis A. Aguilar-Arevalo ◽  
Dairo J. Polo-Toledo

We present a neutrino oscillation analysis of two particular data sets from the Daya Bay and RENO reactor neutrino experiments aiming to study the increase in precision in the oscillation parameters sin22θ13 and the effective mass splitting Δmee2 gained by combining two relatively simple to reproduce analyses available in the literature. For Daya Bay, the data from 217 days between December 2011 and July 2012 were used. For RENO, we used the data from 500 live days between August 2011 and January 2012. We reproduce reasonably well the results of the individual analyses, both rate-only and spectral, defining a suitable χ2 statistic for each case. Finally, we performed a combined spectral analysis and extract tighter constraints on the parameters, with an improved precision between 30 and 40% with respect to the individual analyses considered.

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.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Sin Kyu Kang ◽  
Yeong-Duk Kim ◽  
Young-Ju Ko ◽  
Kim Siyeon

The masses of sterile neutrinos are not yet known, and depending on the orders of magnitudes, their existence may explain reactor anomalies or the spectral shape of reactor neutrino events at 1.5 km baseline detector. Here, we present four-neutrino analysis of the results announced by RENO and Daya Bay, which performed the definitive measurements ofθ13based on the disappearance of reactor antineutrinos at km order baselines. Our results using 3 + 1 scheme include the exclusion curve ofΔm412versusθ14and the adjustment ofθ13due to correlation withθ14. The value ofθ13obtained by RENO and Daya Bay with a three-neutrino oscillation analysis is included in the1σinterval ofθ13allowed by our four-neutrino analysis.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yong Du ◽  
Hao-Lin Li ◽  
Jian Tang ◽  
Sampsa Vihonen ◽  
Jiang-Hao Yu

Abstract The Standard Model Effective Field Theory (SMEFT) provides a systematic and model-independent framework to study neutrino non-standard interactions (NSIs). We study the constraining power of the on-going neutrino oscillation experiments T2K, NOνA, Daya Bay, Double Chooz and RENO in the SMEFT framework. A full consideration of matching is provided between different effective field theories and the renormalization group running at different scales, filling the gap between the low-energy neutrino oscillation experiments and SMEFT at the UV scale. We first illustrate our method with a top- down approach in a simplified scalar leptoquark model, showing more stringent constraints from the neutrino oscillation experiments compared to collider studies. We then provide a bottom-up study on individual dimension-6 SMEFT operators and find NSIs in neutrino experiments already sensitive to new physics at ∼20 TeV when the Wilson coefficients are fixed at unity. We also investigate the correlation among multiple operators at the UV scale and find it could change the constraints on SMEFT operators by several orders of magnitude compared with when only one operator is considered. Furthermore, we find that accelerator and reactor neutrino experiments are sensitive to different SMEFT operators, which highlights the complementarity of the two experiment types.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Pilar Coloma ◽  
Patrick Huber ◽  
Thomas Schwetz

AbstractA considerable experimental effort is currently under way to test the persistent hints for oscillations due to an eV-scale sterile neutrino in the data of various reactor neutrino experiments. The assessment of the statistical significance of these hints is usually based on Wilks’ theorem, whereby the assumption is made that the log-likelihood is $$\chi ^2$$ χ 2 -distributed. However, it is well known that the preconditions for the validity of Wilks’ theorem are not fulfilled for neutrino oscillation experiments. In this work we derive a simple asymptotic form of the actual distribution of the log-likelihood based on reinterpreting the problem as fitting white Gaussian noise. From this formalism we show that, even in the absence of a sterile neutrino, the expectation value for the maximum likelihood estimate of the mixing angle remains non-zero with attendant large values of the log-likelihood. Our analytical results are then confirmed by numerical simulations of a toy reactor experiment. Finally, we apply this framework to the data of the Neutrino-4 experiment and show that the null hypothesis of no-oscillation is rejected at the 2.6 $$\sigma $$ σ level, compared to 3.2 $$\sigma $$ σ obtained under the assumption that Wilks’ theorem applies.


2014 ◽  
Vol 29 (16) ◽  
pp. 1430016 ◽  
Author(s):  
Xin Qian ◽  
Wei Wang

We review the current-generation short-baseline reactor neutrino experiments that have firmly established the third neutrino mixing angle θ13 to be nonzero. The relative large value of θ13 (around 9°) has opened many new and exciting opportunities for future neutrino experiments. Daya Bay experiment with the first measurement of [Formula: see text] is aiming for a precision measurement of this atmospheric mass-squared splitting with a comparable precision as [Formula: see text] from accelerator muon neutrino experiments. JUNO, a next-generation reactor neutrino experiment, is targeting to determine the neutrino mass hierarchy (MH) with medium baselines (~ 50 km). Beside these opportunities enabled by the large θ13, the current-generation (Daya Bay, Double Chooz, and RENO) and the next-generation (JUNO, RENO-50, and PROSPECT) reactor experiments, with their unprecedented statistics, are also leading the precision era of the three-flavor neutrino oscillation physics as well as constraining new physics beyond the neutrino Standard Model.


2013 ◽  
Vol 28 (31) ◽  
pp. 1350131 ◽  
Author(s):  
SRINU GOLLU ◽  
K. N. DEEPTHI ◽  
R. MOHANTA

The recent results from Daya Bay and RENO reactor neutrino experiments have firmly established that the smallest reactor mixing angle θ13 is nonvanishing at the 5 σ level, with a relatively large value, i.e. θ13 ≈ 9°. Using the fact that the neutrino mixing matrix can be represented as [Formula: see text], where Ul and Uν result from the diagonalization of the charged lepton and neutrino mass matrices and Pν is a diagonal matrix containing the Majorana phases and assuming the tri-bimaximal (TBM) form for Uν, we investigate the possibility of accounting for the large reactor mixing angle due to the corrections of the charged lepton mixing matrix. The form of Ul is assumed to be that of CKM mixing matrix of the quark sector. We find that with this modification it is possible to accommodate the large observed reactor mixing angle θ13. We also study the implications of such corrections on the other phenomenological observables.


2006 ◽  
Vol 21 (08n09) ◽  
pp. 1855-1868 ◽  
Author(s):  
ALAN W. P. POON

Over the last several years, experiments have conclusively demonstrated that neutrinos are massive and that they mix. There is now direct evidence for νe s from the Sun transforming into other active flavors while en route to the Earth. The disappearance of reactor [Formula: see text], predicted under the assumption of neutrino oscillation, has also been observed. In this paper, recent results from solar and reactor neutrino experiments and their implications are reviewed. In addition, some of the future experimental endeavors in solar and reactor neutrinos are presented.


2007 ◽  
Vol 22 (20) ◽  
pp. 3407-3428 ◽  
Author(s):  
H. SUGIYAMA ◽  
O. YASUDA

Using an analytical approach, the sensitivity to sin 2 2θ13 with infinite statistics in a spectral analysis is investigated in reactor neutrino oscillation experiments with one reactor and two identical detectors. We derive an useful formula for the sensitivity which depends only on two parameters [Formula: see text] (the uncorrelated bin-to-bin systematic error over the square-root of the number of bins) and σ dB (the bin-to-bin correlated detector specific systematic error) if they are smaller than other errors. It is pointed out that the spectrum analysis is advantageous over the rate analysis in search of neutrino oscillations for [Formula: see text].


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Chang Dong Shin ◽  
Kyung Kwang Joo

For over fifty years, reactor experiments have played an important role in neutrino physics, in both discoveries and precision measurements. One of the methods to verify the existence of neutrino is the observation of neutrino oscillation phenomena. Electron antineutrinos emitted from a reactor provide the measurement of the small mixing angleθ13, providing rich programs of neutrino properties, detector development, nuclear monitoring, and application. Using reactor neutrinos, future reactor neutrino experiments, more precise measurements ofθ12,  Δm122, and mass hierarchy will be explored. The precise measurement ofθ13would be crucial for measuring the CP violation parameters at accelerators. Therefore, reactor neutrino physics will assist in the complete understanding of the fundamental nature and implications of neutrino masses and mixing. In this paper, we investigated several characteristics of RENO-50, which is a future medium-baseline reactor neutrino oscillation experiment, by using the GloBES simulation package.


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