Determination Of Oscillation Parameters Research Articles

Simulation of the rotary-screw vehicle motion on snow

The article presents the determination of oscillation parameters of the rotor-screw vehicle during motion on rough terrain. The study presented the dynamics of off-road vehicle movement. The dependence of the vehicle vibration characteristics on the mover geometry and suspension parameters was found. The experiment with the vehicle was performed. Analysis of the research results allows to conclude that the use of the suspension increases speed of the rotary-screw vehicle by 1.5 - 2.5 times. The developed model and obtained results will be useful in design of all-terrain vehicles.

Progress in neutrino-nuclear scattering

Neutrino-nuclear interactions are an integral part of accelerator based measurements of neutrino oscillation. However, the presence of significant nuclear effects complicates our understanding and can be a source of bias in the determination of oscillation parameters. The modeling of nuclear effects can be tested against new measurements made with a range of target materials and incident beams. Answers to outstanding questions in neutrino nuclear scattering are presented based on recent results from T2K, MINERνA, NOνA and ArgoNeuT experiments, alongside new questions and puzzles.

Neutrino Cross Sections and Oscillation Parameters

The quantitative understanding of how the description of nuclear dynamics affects the neutrino-nucleus cross sections—needed to reduce the systematic uncertainty of long baseline neutrino oscillation experiments—involves severe difficulties. In this paper, I review the status and prospects of theoretical studies of neutrino-nucleus interactions, and briefly discuss the influence of the treatment of nuclear effects on the determination of oscillation parameters.

Super-Kamiokande Low Energy Results

Super-Kamiokande (SK) currently continues data taking as the fourth phase of the experiment (SK-IV). Because of improvements in the water circulation system, the background in the low energy region was reduced and solar neutrino signals are observed even at 3.5–4.0 MeV kinetic energy. Consequently, the SK solar neutrino measurement provided better determination of oscillation parameters (θ12 and Δm212) and checks on the matter effects of oscillations. SK also has been searching for galactic supernovae. The SK-I to III limit on the flux of supernova relic neutrinos (SRN) has reached near the predictions of several models. In order to detect the SRN signal, tagging neutrons is necessary. For this purpose, a prototype gadolinium-loaded water Cherenkov detector has been constructed.

Nuclear Effects in Neutrino Interactions and Their Impact on the Determination of Oscillation Parameters

The quantitative description of the effects of nuclear dynamics on the measured neutrino-nucleus cross sections—needed to reduce the systematic uncertainty of long baseline neutrino oscillation experiments—involves severe difficulties. Owing to the uncertainty on the incoming neutrino energy, different reaction mechanisms contribute to the cross section measured at fixed energy and scattering angle of the outgoing lepton, and must therefore be consistently taken into account within a unified model. We research the theoretical approach based on the impulse approximation and the use of realistic nucleon spectral functions, allowing one to describe a variety of reaction mechanisms active in the broad kinematical range covered by neutrino experiments. The extension of this scheme to include more complex mechanisms involving the two-nucleon currents, which are believed to be important, is also outlined. The impact of nuclear effects on the determination of neutrino oscillation parameters is illustrated by analyzing the problem of neutrino energy reconstruction.

About estimations of a one-photon background in neutrino-oscillation experiments at low neutrino energies

The possible sources of one-photon radiation as a background for the quasi-elastic reaction ν µ + n → µ− + p are considered. They are relevant in experiments on determination of oscillation parameters at low neutrino energies (E ν ∼ 1 GeV). The estimation for the cross section of the reaction ν µ + n → µ − + p + γ is given at E lab ν = 0.7 GeV as 0.65% of the corresponding cross section of quasielastic reaction. The mechanisms of quasi-elastic reaction are also considered at low neutrino energies on a quark level.