Abstract: A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GWth nuclear power reactors of the Daya Bay and Ling Ao nuclear power facilities served as intense sources of νe’s. Comparison of the νe rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (∼1500–1950 m ) relative to detectors near the reactors (∼350–600 m ) allowed a precise measurement of νe disappearance. More than 2.5 million νe inverse beta-decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (December, 2011–July, 2012) with a subsequent 1013 days using the complete configuration of eight detectors (October, 2012–July, 2015). The νe rate observed at the far detectors relative to the near detectors showed a significant deficit, R=0.949±0.002(stat)±0.002(syst). The energy dependence of νe disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle sin^2 2θ_(13)=0.0841±0.0027(stat)±0.0019(syst) and the effective neutrino mass-squared difference of |Δm^2_(ee)|=(2.50±0.06(stat)±0.06(syst))×10^(−3) eV^2. Analysis using the exact three-flavor probability found Δm^2_(32)=(2.45±0.06(stat)±0.06(syst))×10^(−3) eV^2 assuming the normal neutrino mass hierarchy and Δm^2_(32)=(−2.56±0.06(stat)±0.06(syst))×10^(−3) eV^2 for the inverted hierarchy.
TL;DR: In this paper, a new global fit of neutrino oscillation parameters within the simplest three-neutrino picture was presented, including new data which appeared since their previous analysis.
TL;DR: In this article, the authors discuss current limits on absolute neutrino mass observables by performing a global data analysis that includes the latest results from oscillation experiments, including the latest decay bounds from the KamLAND-Zen experiment, and constraints from representative combinations of Planck measurements and other cosmological data sets.
Abstract: Within the standard three-neutrino framework, the absolute neutrino masses and their ordering (either normal, NO, or inverted, IO) are currently unknown. However, the combination of current data coming from oscillation experiments, neutrinoless double beta ($0\ensuremath{
u}\ensuremath{\beta}\ensuremath{\beta}$) decay searches, and cosmological surveys, can provide interesting constraints for such unknowns in the sub-eV mass range, down to $O({10}^{\ensuremath{-}1})\text{ }\text{ }\mathrm{eV}$ in some cases. We discuss current limits on absolute neutrino mass observables by performing a global data analysis that includes the latest results from oscillation experiments, $0\ensuremath{
u}\ensuremath{\beta}\ensuremath{\beta}$ decay bounds from the KamLAND-Zen experiment, and constraints from representative combinations of Planck measurements and other cosmological data sets. In general, NO appears to be somewhat favored with respect to IO at the level of $\ensuremath{\sim}2\ensuremath{\sigma}$, mainly by neutrino oscillation data (especially atmospheric), corroborated by cosmological data in some cases. Detailed constraints are obtained via the ${\ensuremath{\chi}}^{2}$ method, by expanding the parameter space either around separate minima in NO and IO or around the absolute minimum in any ordering. Implications for upcoming oscillation and nonoscillation neutrino experiments, including $\ensuremath{\beta}$-decay searches, are also discussed.
428 citations
Cites background from "Measurement of electron antineutrin..."
...The more complete update presented herein (circa 2017) includes, with respect to [9]: (i) the latest results from the long-baseline accelerator experiments T2K [42] and NOvA [43, 44]; (ii) the latest far/near spectral ratio from the reactor neutrino experiment Daya Bay [45]; (iii) the most recent atmospheric neutrino data from the Super-Kamiokande (SK) phase IV [46, 47]....
[...]
...Concerning SBL reactor data, we include the most recent results from the Daya Bay experiment [7] and the Reactor Experiment for Neutrino Oscillation (RENO) [8]; they dominate the current constraints on θ13 and, at the same time, provide a measurement of ∆m
2 independent from accelerator and atmospheric data....
[...]
...[7] D. Adey et al. [Daya Bay Collaboration], “Measurement of the Electron Antineutrino Oscillation with 1958 Days of Operation at Daya Bay,” Phys....
TL;DR: In this paper, the possibility to explain the anomalies in short-baseline neutrino oscillation experiments in terms of sterile neutrinos was discussed, based on an analysis that relies solely on the relative comparison of measured reactor spectra.
Abstract: We discuss the possibility to explain the anomalies in short-baseline neutrino oscillation experiments in terms of sterile neutrinos. We work in a 3 + 1 framework and pay special attention to recent new data from reactor experiments, IceCube and MINOS+. We find that results from the DANSS and NEOS reactor experiments support the sterile neutrino explanation of the reactor anomaly, based on an analysis that relies solely on the relative comparison of measured reactor spectra. Global data from the νe disappearance channel favour sterile neutrino oscillations at the 3σ level with Δm
41
2
≈ 1.3 eV2 and |Ue4| ≈ 0.1, even without any assumptions on predicted reactor fluxes. In contrast, the anomalies in the νe appearance channel (dominated by LSND) are in strong tension with improved bounds on νμ disappearance, mostly driven by MINOS+ and IceCube. Under the sterile neutrino oscillation hypothesis, the p-value for those data sets being consistent is less than 2.6 × 10−6. Therefore, an explanation of the LSND anomaly in terms of sterile neutrino oscillations in the 3 + 1 scenario is excluded at the 4.7σ level. This result is robust with respect to variations in the analysis and used data, in particular it depends neither on the theoretically predicted reactor neutrino fluxes, nor on constraints from any single experiment. Irrespective of the anomalies, we provide updated constraints on the allowed mixing strengths |Uα4| (α = e, μ, τ ) of active neutrinos with a fourth neutrino mass state in the eV range.
295 citations
Cites background or methods from "Measurement of electron antineutrin..."
...For the latter we include the ratios of spectra measured in experimental halls (EH) 3 and 1, and in experimental halls 2 and 1 [71], as well as the measurement of the individual neutrino fluxes from each fissible isotope [37]....
[...]
...Daya Bay spectrum [71] spectral ratios EH3/EH1 and EH2/EH1...
TL;DR: In this paper, the current status of the neutrino oscillation parameter determination is summarized and the conditions on the non-standard interaction parameters under which the precision measurement of neutrinos oscillation parameters can be distorted.
Abstract: Current neutrino experiments are measuring the neutrino mixing parameters with an unprecedented accuracy. The upcoming generation of neutrino experiments will be sensitive to subdominant oscillation effects that can give information on the yet-unknown neutrino parameters: the Dirac CP-violating phase, the mass ordering and the octant of $\theta_{23}$. Determining the exact values of neutrino mass and mixing parameters is crucial to test neutrino models and flavor symmetries designed to predict these neutrino parameters. In the first part of this review, we summarize the current status of the neutrino oscillation parameter determination. We consider the most recent data from all solar experiments and the atmospheric data from Super-Kamiokande, IceCube and ANTARES. We also implement the data from the reactor neutrino experiments KamLAND, Daya Bay, RENO and Double Chooz as well as the long baseline neutrino data from MINOS, T2K and NOvA. If in addition to the standard interactions, neutrinos have subdominant yet-unknown Non-Standard Interactions (NSI) with matter fields, extracting the values of these parameters will suffer from new degeneracies and ambiguities. We review such effects and formulate the conditions on the NSI parameters under which the precision measurement of neutrino oscillation parameters can be distorted. Like standard weak interactions, the non-standard interaction can be categorized into two groups: Charged Current (CC) NSI and Neutral Current (NC) NSI. Our focus will be mainly on neutral current NSI because it is possible to build a class of models that give rise to sizeable NC NSI with discernible effects on neutrino oscillation. These models are based on new $U(1)$ gauge symmetry with a gauge boson of mass $\lesssim 10$~MeV. The UV complete model should be of course electroweak invariant which in general implies that along with neutrinos, charged fermions also acquire new interactions on which there are strong bounds. We enumerate the bounds that already exist on the electroweak symmetric models and demonstrate that it is possible to build viable models avoiding all these bounds. In the end, we review methods to test these models and suggest approaches to break the degeneracies in deriving neutrino mass parameters caused by NSI.
TL;DR: This book gives a simple overview and a logical development of the subject, and together with the DARE package enables the user to obtain a digital simulation of a continuous system without becoming overly involved in the intracacies of the simulation language itself.
Abstract: introduces the reader to the DARE P simulation system. The DARE P system is an equation-oriented continuous system simulation language developed by the authors at the University of ArizonaIt is designed for batch-mode processing, and the system programs are coded in ASNI Fortran IV. Several examples from the disciplines of electrical circuits, control systems, and aerospace engineering are given to illustrate the versatility of the DARE P system. In Chapter 5 the design and application of minicomputer interactive stimulation systems is described with particular reference to the DARE/ELEVEN system. Chapter 6 describes methods for increasing the computing speed of the simulation language. A comparison of the performance of different simulation-language systems is also given. Appendix A contains a discussion of integration routines. Appendix B contains Fortran subroutines while Appendix C discusses numerical techniques. Since the general purpose digital computer is replacing the analog computer as the primary tool of engineers and scientists for the simulation of continuous time systems, a book on this subject is important to the scientific community. This book is valuable in that it gives a simple overview and a logical development of the subject, and together with the DARE package enables the user to obtain a digital simulation of a continuous system without becoming overly involved in the intracacies of the simulation language itself. In our opinion this book provides a good introduction to the subject of digital simulation of continuous systems. It is not suitable as a classroom textbook. However, to those who avail themselves of the DARE system (the programs are available from the authors at a nominal cost) it would serve as a valuable companion to the users’ manual. Unfortunately the book is difficult to read. The authors use specific terms and phrases without adequately defining them. In many instances the narration is too brief and confusing. The technique of providing explanations under the figures themselves rather than in the main body of the text makes for disjointed reading.
"Measurement of electron antineutrin..." refers methods in this paper
...The other copy was sent to a CR-(RC)(4) pulse shaping circuit which provided an integral measure of the incoming signal charge with a ∼100 ns time constant [34]....
TL;DR: The AMANDA-II data collected during the period 2000-2003 have been analysed in a search for a diffuse flux of high-energy extra-terrestrial muon neutrinos from the sum of all sources in the Universe as mentioned in this paper.
Abstract: The AMANDA-II data collected during the period 2000–2003 have been analysed in a search for a diffuse flux of high-energy extra-terrestrial muon neutrinos from the sum of all sources in the Universe. With no excess events seen, an upper limit of Eν × dNν/dEν< 7.4×10−8 GeV cm−2 s−1 sr−1was obtained. The sensitivity of the diffuse analysis of IceCube 9 string for 137 days of data is calculated to be Eν × dNν/dEν< 1.3× 10−7 GeV cm−2 s−1 sr−1. No excess events are observed, which confirms the AMANDA-II upper limit.
617 citations
"Measurement of electron antineutrin..." refers background in this paper
...• the disappearance of νμ produced by particle interactions in the upper atmosphere [71, 72], with energies >1 GeV and baselines up to the diameter of the Earth....