Search results for "high"
showing 10 items of 25798 documents
IceCube Oscillations: 3 years muon neutrino disappearance data
2015
In the 1990s, Super-Kamiokande’s measurements of atmospheric neutrinos led to the acceptance of the mass-induced oscillation model. As of today, the three mixing angles, the solar mass splitting and the absolute value of the atmospheric mass splitting that control the oscillation phenomenon have been measured. We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 GeV and 100 GeV, where a strong disappearance signal is expected.
Neutrino Flavor Sensitivity of Large Liquid Scintillator Detectors
2015
Abstract Scintillator detectors are known for their good light yield, energy resolution, timing characteristics and pulse shape discrimination capabilities. These features make the next-generation liquid scintillation detector LENA[1] (Low Energy Neutrino Astronomy) the optimal choice for a wide range of astro-particle topics including supernova-, solar-, and geo neutrinos. In addition to the excellent calorimetric and timing properties, scintillartor detectors (LSDs) are also capable of topology reconstruction sufficient to discriminate with adequate efficiency between electron and muon neutrino induced charge current events and neutral current events in the GeV energy range. This feature …
Neutrino Flavor Sensitivity of Large Liquid Scintillator Detectors
2015
Scintillator detectors are known for their good light yield, energy resolution, timing characteristics and pulse shape discrimination capabilities. These features make the next-generation liquid scintillation detector LENA[1] (Low Energy Neutrino Astronomy) the optimal choice for a wide range of astro-particle topics including supernova-, solar-, and geo neutrinos. In addition to the excellent calorimetric and timing properties, scintillartor detectors (LSDs) are also capable of topology reconstruction sufficient to discriminate with adequate efficiency between electron and muon neutrino induced charge current events and neutral current events in the GeV energy range. This feature makes LEN…
Measurement of atmospheric neutrino oscillations with three years of data from the full sky.
2018
Initial release related to the measurement of atmospheric neutrino oscillations using three years of neutrino data from the full sky. IceCube results published in Physical Review Letters are competitive for the first time with the best measurements to date. Release limited to Δχ² maps in the (Δm², sin²(θ_23)) space for both the normal and inverted mass ordering. Additional information will be provided as follow-up data analyses are completed by the IceCube Collaboration.
Coherence in neutrino oscillations
2011
The theory of neutrino oscillations has turned out to be the most reasonable explanation to the observed violations in lepton number conservation of solar and atmospheric neutrino fluxes. A derivation of the most important results of this theory is first given using a plane wave treatment and subsequently using a three-dimensional shape-independent wave packet approach. Both methods give the same oscillation patterns, but only the latter one serves as a decent starting point for analyzing coherence in neutrino oscillations. A numerical analysis of the oscillation patterns on various distance scales is also given to graphically illustrate the phenomenon of neutrino oscillation and loss of co…
Phenomenology of non-standard neutrino interactions
2016
Today neutrino physics is in a privileged position within the fascinating field of particle physics. From the discovery of neutrino oscillations by Super-Kamiokande in 1998, the door to physics beyond the Standard Model (SM in what follows) has been opened. This fact implies that neutrinos have to be massive in opposition to the Standard Model assumption. However, this is not a surprise completely, but it was already hinted from theoretical and experimental observations in the two decades prior to the discovery of the oscillatory phenomenon, as neutrino masses included in unification models or the observed deficit of the atmospheric and solar neutrino fluxes. As a consequence of this new pa…
Numerical studies on neutrino oscillation physics in long baseline experiments
2018
This thesis examines the prospects of future long baseline neutrino oscillation experiments. Using computer simulation techniques, we calculate the experimental sensitivities for two experimental configurations in a set of important questions which are all relevant for modern day neutrino physics. First, we set focus on the determination of the θ23 octant, where the aim is to find whether the atmospheric neutrino mixing angle θ23 lies in the high octant, θ23 > 45◦, or in the low octant, θ23 < 45◦. On the other hand, we study how well the long baseline experiments could test the limits of the Standard Model by seeking deviations from the oscillation patterns that follow from the standard three…
Search for sterile neutrinos in the CC verbatim_mark>mathend000# mode at the new CERN-SBLNF
2013
The possible existence of non-active neutrinos for the ElectroWeak interactions was first proposed in 1967 by B. Pontecorvo who named them "sterile" neutrinos. Recent tensions among world-wide experimental data renewed the possibility of one or more sterile neutrino states. Several "anomalies" emerged in radioactive sources and reactor neutrino experiments, as well as the long-standing LSND and the recent MiniBooNE hints for neutrino and antineutrino oscillations with a δm2 at the eV2 scale, not compatible with the standard 3 × 3 neutrino mixing scenario. While a huge effort is being devoted to establish the standard three-neutrino mixing paradigm no conclusive experiment was carried out to…
Search for a diffuse flux of high-energy ¿µ with the ANTARES neutrino telescope
2011
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A $(0.83\times 2\pi)$ sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an $E^{-2}$ flux spectrum, a 90% c.l. upper limit on the diffuse $\nu_\mu$ flux of $E^2\Phi_{90%} = 5.3 \times 10^{-8} \ \mathrm{GeV\ cm^{-2}\ s^{-1}\ sr^{-1}} $ in the energy range 20 TeV - 2.5 PeV is obtained. Other signal models with differ…
Neutrino masses and their implications for low energy experiments and the LHC
2020
Neutrino oscillations constitute the first experimental evidence of new physics. Con- trary to the prediction of the Standard Model, neutrinos are now well-established as particles with mass. In this thesis we study four topics related to neutrino masses. We examine a class of patterns of Majorana neutrino mass matrices, called two-zero textures, that could lead to the building of the underlying flavour theory. Using a purely numerical technique, we compare the constraints given by the textures with the most updated data of oscillation parameters. We find that the most promising textures are those of class A with normal ordering. Further, we revisit the case of excluded textures and study t…