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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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The main goal of the JUNO experiment is the determination of the neutrino mass ordering. To achieve this, an extraordinary energy resolution of at least 3 % at 1 MeV is required for which all parts ...of the JUNO detector need to meet certain quality criteria. This is relevant in particular for those which are related to the energy resolution of the detector, such as the photomultiplier tubes (PMTs) to be deployed in JUNO. This paper presents the setup and performance of a dedicated PMT mass testing facility to examine and characterize the performance of the 20-inch JUNO PMTs. Its quasi-industrial size and operation level allows to test all 20000 PMTs intended to be used in the JUNO experiment. With this PMT mass testing system, several key characteristics like dark count rate, peak-to-valley ratio, photon detection efficiency, and timing resolution have been determined at an operating gain of 1 נ107 and assessed with respect to the requirements of JUNO. Measurement conditions and modes for the PMTs as well as estimated accuracies for the determination of the individual PMT parameters with the system are presented as well.
A modular liquid argon (LAr) Time Projection Chamber (TPC) with pixelated charge readout is considered as a part of the near-detector for the Deep Underground Neutrino Experiment (DUNE) 1. Such a TPC ...is being developed by the ArgonCube collaboration 2. To provide a trigger for the data acquisition (DAQ) of a neutrino event the LAr scintillation light detection is proposed. The light is a vacuum ultraviolet (UV) with 128 nm wavelength, thus, it is a challenge to register it. The main requirements imposed on the light detection system are a good performance at cryogenic temperatures, non-conductive materials, compact dimensions, and a detection efficiency at a level of percent. A Light Collection Module (LCM) as a candidate for the system has been developed at Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The LCM is based on the wavelength-shifting (WLS) fibers that are coated with Tetraphenyl Butadiene (TPB) and read out by silicon photomultipliers (SiPM). Also at JINR, a full readout chain for the light detection system has been developed, consisting of the front-end electronics, power-supply for the SiPMs, and the DAQ. A cryogenic test setup has been built at JINR to study the performance of the LCM in LAr. A similar study was carried out in the laboratory for high energy physics of Bern University with highly purified LAr. These studies have shown that the photon detection efficiency (PDE) of the LCM for the LAr scintillation light is about 1–2%. Further tests in the ArgonCube prototype TPC will provide the real performance of the LCM system with a full readout chain.
A single-line symbolic notation is proposed for description of an arbitrary multibody system. The kinematics is represented by a sequence of elementary transformations, each of those being marked by ...a reserved alphabetic character. Force and constraint links between the bodies are also defined by reserved characters. The parameters of the system, such as identifiers of degrees of freedom, inertia parameters and others, are assigned default names if not specified. However, user-defined names, parameters and functions can be placed instead if needed. The proposed description in its shortest form is suitable for academic purpose to identify only the essential properties of a multibody system. In an extended form, by explicit mentioning names of variables and parameters and other data like initial conditions, this description can serve as input data for a multibody analysis software. Lots of examples from the academic area and technical applications are given to show the applicability of the description.
Our goal was to study the effectiveness of resveratrol in correcting cognitive impairments and in normalization of neurotrophin levels in patients with type II diabetes mellitus. Material and Methods ...― In a randomized placebo-controlled trial, 100 patients with a verified diagnosis of type II diabetes mellitus took part, who were subsequently placed into two groups: the treatment group of 50 patients taking a polyphenol therapeutic drug in addition to standard therapy, and the comparison group of 50 indivuduals taking a placebo medication in addition to standard therapy. The control group consisted of 30 individuals belonging to the health group I sensu RF Ministry of Healthcare. Treatment efficacy was assessed using the Montreal Cognitive Assessment (MoCA) scale. The concentrations of insulin-like growth factor 1 (IFR-1), brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) in blood plasma were analyzed before and after treatment completion (10 weeks later). Results ― Before starting treatment, patients exhibited an increase in the level of IFR-1 and a decrease in the content of neurotrophic factors (BDNF and NGF) in their blood plasma. In patients receiving resveratrol in addition to standard treatment, changes in IFR-1, BDNF and NGF in blood plasma were more noticeable relative to the comparison group and approached the values of the control group. According to the MoCA scale, more pronounced dynamics of cognitive functions was observed in patients of the treatment group. Conclusion ― The high efficiency of the polyphenol therapeutic drug resveratrol in the correction of cognitive impairments in patients with type II diabetes mellitus was established. The use of resveratrol promoted the normalization of the levels of IFR-1 and neurotrophic factors in the blood plasma: in the treatment group, a more pronounced statistically significant decrease in the concentration of IFR-1, along with an increase in BDNF and NGF levels, were observed relative to the control group. The clinically significant effect of resveratrol was in the reduction of cognitive deficit symptoms, which was confirmed by the data of dynamic monitoring on the MoCA scale: in treatment group, there was a statistically significant improvements of optical and spatial functions, attention, abstract thinking, and fulfilling delayed reproduction task; in the comparison group, there was a statistically significant improvement solely of completing delayed reproduction task.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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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.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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}.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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