705 research outputs found
Unbinned test of time-dependent signals in real-time neutrino oscillation experiments
Real-time neutrino oscillation experiments such as Super-Kamiokande (SK), the
Sudbury Neutrino Observatory (SNO), the Kamioka Liquid scintillator
Anti-Neutrino Detector (KamLAND), and Borexino, can detect time variations of
the neutrino signal, provided that the statistics is sufficiently high. We
quantify this statement by means of a simple unbinned test, whose sensitivity
depends on the variance of the signal in the time domain, as well as on the
total number of signal and background events. The test allows a unified
discussion of the statistical uncertainties affecting current or future
measurements of eccentricity-induced variations and of day-night asymmetries
(in SK, SNO, and Borexino), as well as of reactor power variations (in
KamLAND).Comment: 17 pages, including 3 figure
Probing particle and nuclear physics models of neutrinoless double beta decay with different nuclei
Half-life estimates for neutrinoless double beta decay depend on particle
physics models for lepton flavor violation, as well as on nuclear physics
models for the structure and transitions of candidate nuclei. Different models
considered in the literature can be contrasted - via prospective data - with a
"standard" scenario characterized by light Majorana neutrino exchange and by
the quasiparticle random phase approximation, for which the theoretical
covariance matrix has been recently estimated. We show that, assuming future
half-life data in four promising nuclei (Ge-76, Se-82, Te-130, and Xe-136), the
standard scenario can be distinguished from a few nonstandard physics models,
while being compatible with alternative state-of-the-art nuclear calculations
(at 95% C.L.). Future signals in different nuclei may thus help to discriminate
at least some decay mechanisms, without being spoiled by current nuclear
uncertainties. Prospects for possible improvements are also discussed.Comment: Minor corrections in the text, references added. Matches published
version in Phys. Rev. D 80, 015024 (2009
Neutrino mass and mixing parameters: A short review
We present a brief review of the current status of neutrino mass and mixing
parameters, based on a comprehensive phenomenological analysis of neutrino
oscillation and non-oscillation searches, within the standard three-neutrino
mixing framework.Comment: 11 pages, including 7 figures. Presented at the 40th Rencontres de
Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta
Valley, Italy, 5-12 Mar 200
Mantle geoneutrinos in KamLAND and Borexino
The KamLAND and Borexino experiments have observed, each at ~4 sigma level,
signals of electron antineutrinos produced in the decay chains of thorium and
uranium in the Earth's crust and mantle (Th and U geoneutrinos). Various pieces
of geochemical and geophysical information allow an estimation of the crustal
geoneutrino flux components with relatively small uncertainties. The mantle
component may then be inferred by subtracting the estimated crustal flux from
the measured total flux. To this purpose, we analyze in detail the experimental
Th and U geoneutrino event rates in KamLAND and Borexino, including neutrino
oscillation effects. We estimate the crustal flux at the two detector sites,
using state-of-the-art information about the Th and U distribution on global
and local scales. We find that crust-subtracted signals show hints of a
residual mantle component, emerging at ~2.4 sigma level by combining the
KamLAND and Borexino data. The inferred mantle flux slightly favors scenarios
with relatively high Th and U abundances, within +-1 sigma uncertainties
comparable to the spread of predictions from recent mantle models.Comment: Slight changes and improvements in the text & figures. Results
unchanged. To appear in Phys. Rev.
FRCM-to-masonry bonding behaviour in the case of curved surfaces: Experimental investigation
Fabric-reinforced cementitious matrix (FRCM) are composite materials more and more used for the reinforcement of masonry structures. The combination of high tensile strength fabrics (or meshes) with cementitious matrices, having good thixotropic capabilities and vapour permeability, makes such composites suitable for reinforcing a large number of masonry structures, including the one belonging to the historic heritage. FRCMs are bonded to the outer surfaces of structural masonry elements and, thanks to their adhesive capacity, bear much of the tensile stresses that unreinforced masonry cannot withstand. The effectiveness of such reinforcements, which is highly dependent on their ability to adhere to the masonry substrate, is generally investigated throughout specific experimental investigations (shear tests). Almost all the papers in the literature devoted to bond-slip analysis refer to the case of flat bonding surfaces, although these reinforcements are also widely used on curved structural elements such as arches and vaults. Therefore, this paper reports and examines the results of an extensive experimental program concerning the behavior of FRCM systems applied on curved masonry specimens. The results point out the influence of both curvature and reinforcement position (intrados or extrados) on the response of specimens in terms of bearing capacity, failure mode and post-peak response
Automatic segmentation and classification methods using optical coherence tomography angiography (Octa): A review and handbook
Optical coherence tomography angiography (OCTA) is a promising technology for the non-invasive imaging of vasculature. Many studies in literature present automated algorithms to quantify OCTA images, but there is a lack of a review on the most common methods and their comparison considering multiple clinical applications (e.g., ophthalmology and dermatology). Here, we aim to provide readers with a useful review and handbook for automatic segmentation and classification methods using OCTA images, presenting a comparison of techniques found in the literature based on the adopted segmentation or classification method and on the clinical application. Another goal of this study is to provide insight into the direction of research in automated OCTA image analysis, especially in the current era of deep learning
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