Search results for "electron neutrino"
showing 10 items of 39 documents
Theoretical estimates of supernova-neutrino cross sections for the stable even-even lead isotopes: Charged-current reactions
2016
A detailed study of the charged-current supernova electron neutrino and electron antineutrino scattering off the stable even-mass lead isotopes $A=204$, 206, and 208 is reported in this work. The proton-neutron quasiparticle random-phase approximation (pnQRPA) is adopted to construct the nuclear final and initial states. Three different Skyrme interactions are tested for their isospin and spin-isospin properties and then applied to produce (anti)neutrino-nucleus scattering cross sections for (anti)neutrino energies below 80 MeV. Realistic estimates of the nuclear responses to supernova (anti)neutrinos are computed by folding the computed cross sections with a two-parameter Fermi-Dirac distr…
Beta-decay studies for applied and basic nuclear physics
2020
In this review we will present the results of recent beta-decay studies using the total absorption technique that cover topics of interest for applications, nuclear structure and astrophysics. The decays studied were selected primarily because they have a large impact on the prediction of a) the decay heat in reactors, important for the safety of present and future reactors and b) the reactor electron antineutrino spectrum, of interest for particle/nuclear physics and reactor monitoring. For these studies the total absorption technique was chosen, since it is the only method that allows one to obtain beta decay probabilities free from a systematic error called the Pandemonium effect. The me…
Neutrino interaction classification with a convolutional neural network in the DUNE far detector
2020
The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino…
Reconciling dark matter, solar and atmospheric neutrinos
1993
We present models that can reconcile the solar and atmospheric neutrino data with the existence of a hot dark matter component in the universe. This dark matter is a quasi-Dirac neutrino whose mass $m_{DM}$ arises at the one-loop level. The solar neutrino deficit is explained via nonadiabatic conversions of electron neutrino to a sterile neutrino and the atmospheric neutrino data via maximal muon neutrino to tau neutrino oscillations generated by higher order loop diagrams. For $m_{DM} \sim 30$ eV the radiative neutrino decay can lead to photons that can ionize interstellar hydrogen. In one of the models one can have observable $\nu_e$ to $\nu_\tau$ oscillation rates, with no appreciable mu…
Neutrinoless double electron capture as a tool to measure the electron neutrino mass
1983
Abstract A nucleus (Z, A) may capture two atomic electrons to become (Z − 2, A). For Majorana neutrinos this may occur with no neutrino emission, the process is a virtual mixing of the parent atom and the daughter atom with two electron holes. The process becomes real as the daughter atom de-excites. In some cases where the daughter nucleus is excited, the neutrinoless decay may be enhanced by its proximity to a virtual resonance. We identify the 112 Sn → 112 Cd transition as a good case. The no-neutrino lifetime for mν = 30 eV ranges from 1022 to 1027 years as a function of the insufficiently well determined distance to resonance. The signatures of the two- or no-neutrino modes are very di…
Search for Electron Antineutrino Appearance in a Long-baseline Muon Antineutrino Beam
2020
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 2.40 σ 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 a…
Combining LSND and Atmospheric Anomalies in a Three-Neutrino Picture
2001
We investigate the three-neutrino mixing scheme for solving the atmospheric and LSND anomalies. We find the region in the parameter space that provides a good fit to the LSND and the SK atmospheric data, taking into account the CHOOZ constraint. We demonstrate that the goodness of this fit is comparable to that of the conventional fit to the solar and atmospheric data. Large values of the LSND angle are favoured and $\sin^2(2\theta_{\rm LSND})$ can be as high as 0.1. This can have important effects on the atmospheric electron neutrino ratios as well as on down-going multi-GeV muon neutrino ratios. We examine the possibility of distinguishing this scheme from the conventional one at the long…
The development of the KATRIN magnet system
2006
The Karlsruhe Tritium Neutrino Experiment KATRIN aims to measure the mass of the electron neutrino with unprecedented accuracy. For this experiment a special magnet system with about 30 LHe bath cooled superconducting magnets grouped in 10 different sections needs to be developed. The magnetic fields required for the electron transport and spectrometer resolution have a level between 3 and 6 T and must be constant in time over months. Further requirements for field homogeneity and tritium compatibility lead to a unique magnet system. A challenging task of this system is to keep the 10 m beam tube of the source magnet at a constant temperature of 30 K with extremely high temperature stabilit…
A combined beta-beam and electron capture neutrino experiment
2009
The next generation of long baseline neutrino experiments will aim at determining the value of the unknown mixing angle, theta_{13}, the type of neutrino mass hierarchy and the presence of CP-violation in the lepton sector. Beta-beams and electron capture experiments have been studied as viable candidates for long baseline experiments. They use a very clean electron neutrino beam from the beta-decays or electron capture decays of boosted ions. In the present article we consider an hybrid setup which combines a beta-beam with an electron capture beam by using boosted Ytterbium ions. We study the sensitivity to the CP-violating phase delta and the theta_{13} angle, the CP-discovery potential …
First operation of the KATRIN experiment with tritium
2020
AbstractThe determination of the neutrino mass is one of the major challenges in astroparticle physics today. Direct neutrino mass experiments, based solely on the kinematics of $$\upbeta $$β-decay, provide a largely model-independent probe to the neutrino mass scale. The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to directly measure the effective electron antineutrino mass with a sensitivity of $$0.2\hbox { eV}$$0.2eV ($$90\%$$90% CL). In this work we report on the first operation of KATRIN with tritium which took place in 2018. During this commissioning phase of the tritium circulation system, excellent agreement of the theoretical prediction with the recorded spectra was …