Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target.

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7(16.3)×1020 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7×1020 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin2θ13 and the impact of priors on the δCP measurement. Both analyses prefer the normal mass ordering and upper octant of sin2θ23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin2θ13 from reactors, sin2θ23=0.561-0.032+0.021 using Feldman-Cousins corrected intervals, and Δm322=2.494-0.058+0.041×10-3eV2 using constant Δχ2 intervals. The CP-violating phase is constrained to δCP=-1.97-0.70+0.97 using Feldman-Cousins corrected intervals, and δCP=0,π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2σ credible level using a flat prior in δCP, and just below 2σ using a flat prior in sinδCP. When the external constraint on sin2θ13 is removed, sin2θ13=28.0-6.5+2.8×10-3, in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC.

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration.

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam.

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3} eV^{2}/c^{4}.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K.

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135 µ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66 µ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Measurement of Coherent π

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam.

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{µ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{µ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{µ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained µ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3} eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3} eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{µ} disappearance parameters measured by T2K.

[Methodical issues of the monitoring for ammonium in indoors air].

Introduction. To perform mass studies of the indoors air environment of the ammonium content the actual issues are the shortening of the sampling time and material costs for their implementation, reduction of adverse effects of ammonium with keeping of the objectivity of results. Aim. The elaboration of the method of short-term air sampling for indoors ammonium and comparative assessment ofdifferent methods of sampling in the course of modeling and field tests. Materials and Methods. Air sampling for ammonium was carried out according to the developed program and standard method, under the average daily 4-fold taking according to State Standards (GOST) 17.2.3.01-86 andRD 52.04.186-89. The evaluation of the significance of deviations of analysis results was carried out in accordance with GOST R ISO 5725-6-2002 and Recommendations of the Interstate Standardization RMG - 61-2003. Results. There were executed model and field tests of air sampling for ammonium according to the standard method and the program of short-term sampling. There were obtained significantly comparable results of ammonium content in the indoor air in the course of model and field tests. Conclusions. Sampling according to the developed program has a number of advantages, including: the shortening of sampling time, material costs, increasing in productivity in the analysis of indoor airfor the ammonium content. The execution oftest sampling according to the developed program allows to reduce the time of ammonium exposure to personnel carrying out the test sampling.

Age dependent changes of arterial wall viscoelasticity.

Viscoelastic characteristics (VEC) of old rat aorta (Wistar, 10 months) were obtained by sinusoidal excitation of intraluminal pressure (p) in cylindrical arterial preparations. The pressure excitation frequency (f(exc)) was swept in the range 3-30 Hz up and down at several mean-pressure levels while response volume oscillations were recorded and resonance curves were plotted. Natural frequency (f(0)), dynamic modulus of elasticity (E') and coefficient of viscosity (beta) were estimated from resonance curves and the dependences of VEC on p were drawn. The results showed that f(0) decreased linearly with p whereas our previous data for young rat aorta (Wistar, 4 months) showed independence of f(0) on p. E' increased nonlinearly with p with the values being higher in comparison to young rat aorta. This means stiffening of rat aorta with age in accordance with the known literature data. beta-values increased linearly with p being higher in comparison to young rat aorta, demonstrative of raised intrinsic friction in the wall. VEC values were higher at decreasing f(exc) suggesting that the direction of excitation sweeping also determines the arterial wall biomechanical behaviour. It could be concluded that blood vessels VEC worsen with age, which endangers the arterial wall integrity, especially at higher intraluminal pressure.

An experimental model for study of sialoglycoproteins of human immunodeficiency virus 1 epitope structures.

Sialic acid (SA) molecules located terminally on retrovirus glycoproteins (gps) play a key role in virus-cell interactions. The specificity of sialylation of Human immunodeficiency virus 1 (HIV-1) gps has not yet been studied. Looking for a convenient and reproducible experimental virus-cell model for studying the problem mentioned above we compared viral sialoglycoprotein (Sgp) patterns in H9/HTLV III B cells chronically infected with laboratory-adapted HIV-1LAI and MT-2 cells acutely infected with the same virus. Cytosols (CSs) and supernatant concentrates (SNs) from these cells and cell cultures, respectively, following N-acetyl-D-[U-14C]-mannosamine ([14C]NAcMan) labeling were subjected to preparative isoelectrofocusing and the obtained fractions were assayed for 14C-incorporation, reverse transcriptase (RT) activity and protein content. Sgp patterns in CSs from the two types of infection were similar. Highly sialylated peaks clustered mainly in the acidic region where the highest 14C-incorporation, RT activity and protein content were found. The 14C-incorporation was higher in CS than in SN. Analysis of CS from MT-2 cells infected with HIV-1 for the markers described above seems to be the experimental approach and model of choice for clinical isolates of HIV-1.

[Long-term response of bronchopulmonary system in liquidators of Chernobyl accident].

Liquidators of chernobyl accident consequences were subjected to simultaneous external gamma-beta-radiation and inhalation of particles containing radionuclide aerosols and nonradiation toxic chemicals. findings are typical defects of the liquidators examination: assignment of individuals with pulmonary disorders to post-accident work, misinterpretation of the disease severity with underestimation of previous occupational anamnesis and aggravating role of nonradiation.

Isolation and characterization of [3H]fucose-labeled glycoproteins from the serum of normal rats and rats bearing Zajdela hepatoma.

Specific [3H]fucose-labeled glycoproteins were found in the serum of rats bearing Zajdela hepatoma, which possess different isoelectric points in comparison with serum glycoproteins from normal rats. The electrophoretic profile of the serum glycoproteins is significantly altered. There is approximately a 2.5 times increase of [3H]fucose incorporation into serum glycoproteins from rats with an ascitic form of hepatoma, compared with normal rats and to animals bearing a solid form of the tumor (which have a considerably greater survival). Serum fucoproteins identical for the two forms of hepatoma were isolated, as well as glycoproteins strongly specific for each of the forms.

[Rationale for maximum permissible concentration of arbidole and thiophenol in water reservoirs]. / Obosnovanie predelno dopustimoi kontsentratsii arbidola i tiofenola v vode vodnykh obektov.

Maximum allowable concentrations (MAC) for Arbidole and thiophenoi in water were substantiated. MAC of this substances accordingly are (mg/dm3): 0.04 and 0.002.

[Hygienic standardization of realon and zinc complex IOMC-1 in water reservoirs]. / Gigienicheskoe normirovanie realona i tsinkovogo kompleksa IOMS-1 v vode vodoëmov.

Maximum allowable concentrations of Realon and zinc complex IOMC-1 in water were recommended at levels, accordingly, 0.04 and 2.0 mg/1 with organoleptic signs of action.