Neutrino oscillations are an amazing phenomenon which was suggested for the first time 65 years ago and finally confirmed experimentally about 25 yr ago. It provided an extremely important new ...insight of non-zero neutrino masses most popularly connected to the existence of New Physics beyond the Standard Model. Neutrino oscillation studies continue playing an important role, and there are many ongoing and future experimental projects, as well as theoretical developments aimed to improve our knowledge of oscillation parameters. In this paper, the status and prospects of oscillation measurements are described. This comprises the standard interpretation and also discussion of the existence of additional sterile states of neutrinos.
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The physics of neutrino oscillations is a rapidly developing area of study of the fundamental properties of these particles. In this article, we present the status of an experimental study of ...three-flavor oscillations after the largest conference in neutrino physics (Neutrino 2020). Prospects and unresolved problems are discussed.
Abstract
The Jiangmen underground neutrino observatory (JUNO) is a
neutrino project with a 20-kton liquid scintillator detector located
700-m underground. The large 20-inch PMTs are one of the ...crucial
components of the JUNO experiment aiming for precision neutrino
measurements with better than 3% energy resolution at 1 MeV. The
excellent energy resolution and a large fiducial volume provide many
exciting opportunities for addressing important topics in neutrino
and astroparticle physics. With the container #D at JUNO Pan-Asia
PMT testing and potting station, the features of waterproof potted
20-inch PMTs were measured with JUNO 1F3 electronics prototype in
waveform and charge, which are valuable for a better understanding
of the performance of the waterproof potted PMTs and the JUNO 1F3
electronics. In this paper, the basic features of the JUNO 1F3
electronics prototype run at Pan-Asia will be introduced, followed
by an analysis of the waterproof potted 20-inch PMTs and a
comparison with the results from commercial electronics used by
container #A and #B.
This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of $6.05\times10^{20}$ protons-on-target from the NuMI beam at the Fermi ...National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal mixing ($\theta_{23} = \pi/4$). Assuming the normal mass hierarchy, we find $\Delta m^2 = (2.67 \pm 0.11)\times 10^{-3}$ eV$^2$ and $\sin^2 \theta_{23}$ at the two statistically degenerate values $0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68% confidence level. Finally, our data disfavor the maximal mixing scenario with 2.6 $\sigma$ significance.
Results are reported from an improved measurement of ν_{μ}→ν_{e} transitions by the NOvA experiment. Using an exposure equivalent to 6.05×10^{20} protons on target, 33 ν_{e} candidates are observed ...with a background of 8.2±0.8 (syst.). Combined with the latest NOvA ν_{μ} disappearance data and external constraints from reactor experiments on sin^{2}2θ_{13}, the hypothesis of inverted mass hierarchy with θ_{23} in the lower octant is disfavored at greater than 93% C.L. for all values of δ_{CP}.
This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National ...Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3} eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.
Jiangmen Underground Neutrino Observatory (JUNO) is a next generation liquid scintillator neutrino experiment under construction phase in South China. Thanks to the anti-neutrinos produced by the ...nearby nuclear power plants, JUNO will be able to study the neutrino mass hierarchy, one of the open key questions in neutrino physics. One key ingredient for a successful measurement is to use high speed, high resolution sampling electronics located very close to the detector signal. Linearity in the response of the electronics is another important ingredient for the success of the experiment. During the initial design phase of the electronics, a custom design with the Front-End and Read-Out electronics located very close to the detector analog signal has been developed and successfully tested. The present paper describes the electronics structure and the first tests performed on the prototypes. The electronics prototypes have been tested and they show good linearity response, with a maximum deviation of 1.3% over the full dynamic range (1-1000 p.e.), fulfilling the JUNO experiment requirements.
The cross section of neutrino-induced neutral-current coherent π0 production on a carbon-dominated target is measured in the NOvA near detector. This measurement uses a narrow-band neutrino beam with ...an average neutrino energy of 2.7 GeV, which is of interest to ongoing and future long-baseline neutrino oscillation experiments. The measured, flux-averaged cross section is σ = 13.8 ± 0.9 ( stat ) ± 2.3 ( syst ) × 10−40 cm2 / nucleus , consistent with model prediction. This result is the most precise measurement of neutral-current coherent π 0 production in the few-GeV neutrino energy region.
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