Search results for "oscillation"
showing 10 items of 1257 documents
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…
Chi2 profiles from Valencia neutrino global fit
2021
We provide here the 1D and 2D chi2 profiles from our most recent global fit of neutrino oscillation data (DOI:10.1007/JHEP02(2021)071). The files are available at https://globalfit.astroparticles.es/.
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…
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…
Deep Underground Neutrino Experiment (DUNE) Near Detector Conceptual Design Report
2021
The Deep Underground Neutrino Experiment (DUNE) is an international, world-class experiment aimed at exploring fundamental questions about the universe that are at the forefront of astrophysics and particle physics research. DUNE will study questions pertaining to the preponderance of matter over antimatter in the early universe, the dynamics of supernovae, the subtleties of neutrino interaction physics, and a number of beyond the Standard Model topics accessible in a powerful neutrino beam. A critical component of the DUNE physics program involves the study of changes in a powerful beam of neutrinos, i.e., neutrino oscillations, as the neutrinos propagate a long distance. The experiment co…
Solar neutrino spectroscopy in Borexino
2018
International audience; In more than ten years of operation, Borexino has performed a precision measurement of the solar neutrino spectrum, resolving almost all spectral components originating from the proton-proton fusion chain. The presentation will review the results recently released for the second data taking phase 2012–2016 during which the detector excelled by its unprecedentedly low background levels. New results on the rate of pp, 7Be, pep and 8B neutrinos as well as their implications for solar neutrino oscillations and metallicity are discussed.
Inference of proto-neutron star properties from gravitational-wave data in core-collapse supernovae
2021
The eventual detection of gravitational waves from core-collapse supernovae (CCSN) will help improve our current understanding of the explosion mechanism of massive stars. The stochastic nature of the late post-bounce gravitational wave signal due to the non-linear dynamics of the matter involved and the large number of degrees of freedom of the phenomenon make the source parameter inference problem very challenging. In this paper we take a step towards that goal and present a parameter estimation approach which is based on the gravitational waves associated with oscillations of proto-neutron stars (PNS). Numerical simulations of CCSN have shown that buoyancy-driven g-modes are responsible …
Precise Determination of the Unperturbed 8B Neutrino Spectrum
2012
The measurement was performed at the Kernfysisch Versneller Instituut (KVI) at the University of Groningen, The Netherlands.; A measurement of the final state distribution of the 8B $\beta$ decay, obtained by implanting a 8B beam in a double-sided silicon strip detector, is reported here. The present spectrum is consistent with a recent independent precise measurement performed by our collaboration at the IGISOL facility, Jyvâskylä [O. S. Kirsebom et al., Phys. Rev. C 83, 065802 (2011)]. It shows discrepancies with previously measured spectra, leading to differences in the derived neutrino spectrum. Thanks to a low detection threshold, the neutrino spectrum is for the first time directly ex…
Disrupting neural activity related to awake-state sharp wave-ripple complexes prevents hippocampal learning
2012
Oscillations in hippocampal local-field potentials (LFPs) reflect the crucial involvement of the hippocampus in memory trace formation: theta (4–8 Hz) oscillations and ripples (~200 Hz) occurring during sharp waves are thought to mediate encoding and consolidation, respectively. During sharp wave-ripple complexes (SPW-Rs), hippocampal cell firing closely follows the pattern that took place during the initial experience, most likely reflecting replay of that event. Disrupting hippocampal ripples using electrical stimulation either during training in awake animals or during sleep after training retards spatial learning. Here, adult rabbits were trained in trace eyeblink conditioning, a hippoc…
Long-transient conoscopic pattern technique
1999
0038-1098; Recent results on laser induced anisotropy in terbium gallium garnet are extended to the dynamic regime. We observed that the characteristic conoscopic pattern formation time presents a quadratic dependence on the beam size. The observed pattern intensity is accounted for by a simple analytical formula. The transient refractive index change due to thermal stress in the terbium gallium garnet is determined. (C) 1999 Elsevier Science Ltd. All rights reserved.