The JUNO experiment locates in Jinji town, Kaiping city, Jiangmen city, Guangdong province. The geographic location is east longitude 112 • 31'05' and North latitude 22 • 07'05'. The experimental site is 43 km to the southwest of the Kaiping city, a county-level city in the prefecture-level city Jiangmen in Guangdong province. There are five big cities, Guangzhou, Hong Kong, Macau, Shenzhen, and Zhuhai, all in ∼200 km drive distance, as shown in figure 3.
KamLAND has measured the flux of nu;(e)'s from distant nuclear reactors. We find fewer nu;(e) events than expected from standard assumptions about nu;(e) propagation at the 99.95% C.L. In a 162 ton.yr exposure the ratio of the observed inverse beta-decay events to the expected number without nu;(e) disappearance is 0.611+/-0.085(stat)+/-0.041(syst) for nu;(e) energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded.
The Double Chooz Experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944 ± 0.016 (stat) ± 0.040 (syst) was obtained in 101 days of running at the Chooz Nuclear Power Plant in France, with two 4.25 GW th reactors. The results were obtained from a single 10 m 3 fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a non-zero value of the still unmeasured neutrino mixing parameter sin 2 2θ13. Analyzing both the rate of the prompt positrons and their energy spectrum we find sin 2 2θ13= 0.086 ± 0.041 (stat) ±0.030 (syst), or, at 90% CL, 0.017 < sin 2 2θ13 < 0.16. We report first results of a search for a non-zero neutrino oscillation [1] mixing angle, θ 13 , based on reactor antineutrino disappearance. This is the last of the three neutrino oscillation mixing angles [2,3] for which only upper limits [4,5] are available. The size of θ 13 sets the required sensitivity of long-baseline oscillation experiments attempting to measure CP violation in the neutrino sector or the mass hierarchy.In reactor experiments [6,7] addressing the disappearance ofν e , θ 13 determines the survival probability of electron antineutrinos at the "atmospheric" squaredmass difference, ∆m 2 atm . This probability is given by:where L is the distance from reactor to detector in meters and E the energy of the antineutrino in MeV. The full formula can be found in Ref.[1]. Eq. 1 provides a direct way to measure θ 13 since the only additional input is the well measured value of |∆m 2 atm | = (2.32Other running reactor experiments [9,10] are using the same technique.Electron antineutrinos of < 9 MeV are produced by reactors and detected through inverse beta decay (IBD): ν e + p → e + + n. Detectors based on hydrocarbon liquid scintillators provide the free proton targets. The IBD signature is a coincidence of a prompt positron signal followed by a delayed neutron capture. We present here our first results with a detector located ∼ 1050 m from the two 4.25 GW th thermal power reactors of the Chooz Nuclear Power Plant and under a 300 MWE rock overburden. The analysis is based on 101 days of data including 16 days with one reactor off and one day with both reactors off.The antineutrino flux of each reactor depends on its thermal power and, for the four main fissioning isotopes, 235 U, 239 Pu, 238 U, 241 Pu, their fraction of the total fuel content, their energy released per fission, and their fission and capture cross-sections. The fission rates and associated errors were evaluated using two predictive and complementary reactor simulation codes: MURE [17,18] and DRAGON [19]. This allowed a study of the sensitivity to the important reactor parameters (e.g.. thermal power, boron concentration, temperatures and densities). The quality of these simulations...
The Booster Neutrino Experiment (MiniBooNE) searches for ν µ → ν e oscillations using the O(1 GeV) neutrino beam produced by the Booster synchrotron at the Fermi National Accelerator Laboratory (FNAL). The Booster delivers protons with 8 GeV kinetic energy (8.89 GeV/c momentum) to a beryllium target, producing neutrinos from the decay of secondary particles in the beam line. We describe the Monte Carlo simulation methods used to estimate the flux of neutrinos from the beamline incident on the MiniBooNE detector for both polarities of the focusing horn. The simulation uses the Geant4 framework for propagating particles, accounting for electromagnetic processes and hadronic interactions in the beamline materials, as well as the decay of particles.The absolute double differential cross sections of pion and kaon production in the simulation have been tuned to match external measurements, as have the hadronic cross sections for nucleons and pions. The statistical precision of the flux predictions is enhanced through reweighting and resampling techniques. Systematic errors in the flux estimation have been determined by varying parameters within their uncertainties, accounting for correlations where appropriate.
We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 nu (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor nu (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.
A high-statistics sample of charged-current muon neutrino scattering events collected with the MiniBooNE experiment is analyzed to extract the first measurement of the double differential cross section ( d 2 σ dTµd cos θµ ) for charged-current quasielastic (CCQE) scattering on carbon. This result features minimal model dependence and provides the most complete information on this process to date. With the assumption of CCQE scattering, the absolute cross section as a function of neutrino energy (σ[Eν]) and the single differential cross section ( dσ dQ 2 ) are extracted to facilitate comparison with previous measurements. These quantities may be used to characterize an effective axial-vector form factor of the nucleon and to improve the modeling of low-energy neutrino interactions on nuclear targets. The results are relevant for experiments searching for neutrino oscillations.
The MiniBooNE experiment at Fermilab reports results from an analysis of νe appearance data from 12.84 × 10 20 protons on target in neutrino mode, an increase of approximately a factor of two over previously reported results. A νe charged-current quasielastic event excess of 381.2 ± 85.2 events (4.5σ) is observed in the energy range 200 < E QE ν < 1250 MeV. Combining these data with theνe appearance data from 11.27 × 10 20 protons on target in antineutrino mode, a total νe plus νe charged-current quasielastic event excess of 460.5 ± 99.0 events (4.7σ) is observed. If interpreted in a two-neutrino oscillation model, νµ → νe, the best oscillation fit to the excess has a probability of 21.1%, while the background-only fit has a χ 2 probability of 6 × 10 −7 relative to the best fit. The MiniBooNE data are consistent in energy and magnitude with the excess of events reported by the Liquid Scintillator Neutrino Detector (LSND), and the significance of the combined LSND and MiniBooNE excesses is 6.0σ. A two-neutrino oscillation interpretation of the data would require at least four neutrino types and indicate physics beyond the three neutrino paradigm. Although the data are fit with a two-neutrino oscillation model, other models may provide better fits to the data.Evidence for short-baseline neutrino anomalies at an L/E ν ∼ 1 m/MeV, where E ν is the neutrino energy and L is the distance that the neutrino traveled before detection, comes from both neutrino appearance and disappearance experiments. The appearance anomalies include the excess of ν e andν e charge-current quasielastic (CCQE) events observed by the LSND [1] and MiniBooNE [2,3] experiments, while the disappearance anomalies, although not completely consistent, include the deficit of ν e andν e events observed by reactor [4] and radioactive-source experiments [5]. As the masses and mixings within the 3-generation neutrino matrix have been attached to solar and long-baseline neutrino experiments, more exotic models are typically used to explain these anomalies, including, for example, 3+N neutrino oscillation models involving three active neutrinos and N additional sterile neutrinos [6][7][8][9][10][11][12][13][14], resonant neutrino oscillations [15], Lorentz violation [16], sterile neutrino decay [17], sterile neutrino nonstandard interactions [18], and sterile neutrino extra dimensions [19]. This Letter presents improved MiniBooNE ν e andν e appearance results, assuming two-neutrino oscillations with probability arXiv:1805.12028v2 [hep-ex]
This paper explores the use of L/E oscillation probability distributions to compare experimental measurements and to evaluate oscillation models. In this case, L is the distance of neutrino travel and E is a measure of the interacting neutrino's energy. While comparisons using allowed and excluded regions for oscillation model parameters are likely the only rigorous method for these comparisons, the L/E distributions are shown to give qualitative information on the agreement of an experiment's data with a simple two-neutrino oscillation model. In more detail, this paper also outlines how the L/E distributions can be best calculated and used for model comparisons. Specifically, the paper presents the L/E data points for the final MiniBooNE data samples and, in the Appendix, explains and corrects the mistaken analysis published by the ICARUS collaboration.
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