102 research outputs found
Direct neutrino mass measurements after PLANCK
AbstractThe absolute mass scale of neutrinos remains an open question subject to experimental investigation from both particle physics and cosmology. Over the next decade, a number of experiments from both disciplines will attempt to probe the mass scale further to the very limits of the predictions from oscillation results. This paper provides a broad overview of the experimental program in neutrino mass scale measurements, with a particular focus on direct experimental probes due to come online over the next decade
Measurement of Atmospheric Neutrinos at the Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory consists of a 1 kiloton heavy water Cherenkov detector able to detect and reconstruct high-energy muons created from cosmic ray showers and atmospheric neutrino interactions. By measuring the flux of through-going muons as a function of zenith angle, the SNO experiment can distinguish between the oscillated and un-oscillated portion of the neutrino flux. This report describes SNO's measurements of the flux of cosmic ray muons and neutrino-induced muon flux at a depth of 5890 meters water equivalent
New approach to 3D electrostatic calculations for micro-pattern detectors
We demonstrate practically approximation-free electrostatic calculations of
micromesh detectors that can be extended to any other type of micropattern
detectors. Using newly developed Boundary Element Method called Robin Hood
Method we can easily handle objects with huge number of boundary elements
(hundreds of thousands) without any compromise in numerical accuracy. In this
paper we show how such calculations can be applied to Micromegas detectors by
comparing electron transparencies and gains for four different types of meshes.
We demonstrate inclusion of dielectric material by calculating the electric
field around different types of dielectric spacers
Project 8: Using Radio-Frequency Techniques to Measure Neutrino Mass
The shape of the beta decay energy distribution is sensitive to the mass of
the electron neutrino. Attempts to measure the endpoint shape of tritium decay
have so far seen no distortion from the zero-mass form. Here we show that a new
type of electron energy spectroscopy could improve future measurements of this
spectrum and therefore of the neutrino mass. We propose to detect the coherent
cyclotron radiation emitted by an energetic electron in a magnetic field. For
mildly relativistic electrons, like those in tritium decay, the relativistic
shift of the cyclotron frequency allows us to extract the electron energy from
the emitted radiation. As the technique inherently involves the measurement of
a frequency in a non-destructive manner, it can, in principle, achieve a high
degree of resolution and accuracy.Comment: 5 pages, 3 figures. Submitted to the Neutrino 2010 Conference in
Athens, Greec
Sensitivity to the KARMEN Timing Anomaly at MiniBooNE
We present sensitivities for the MiniBooNE experiment to a rare exotic pion
decay producing a massive particle, Q^0. This type of decay represents one
possible explanation for the timing anomaly reported by the KARMEN
collaboration. MiniBooNE will be able to explore an area of the KARMEN signal
that has not yet been investigated
Background reduction and sensitivity for germanium double beta decay experiments
Germanium detectors have very good capabilities for the investigation of rare
phenomena like the neutrinoless double beta decay. Rejection of the background
entangling the expected signal is one primary goal in this kind of experiments.
Here, the attainable background reduction in the energy region where the
neutrinoless double beta decay signal of 76Ge is expected to appear has been
evaluated for experiments using germanium detectors, taking into consideration
different strategies like the granularity of the detector system, the
segmentation of each individual germanium detector and the application of Pulse
Shape Analysis techniques to discriminate signal from background events.
Detection efficiency to the signal is affected by background rejection
techniques, and therefore it has been estimated for each of the background
rejection scenarios considered. Finally, conditions regarding crystal mass,
radiopurity, exposure to cosmic rays, shielding and rejection capabilities are
discussed with the aim to achieve a background level of 10-3 c keV-1 kg-1 y-1
in the region of interest, which would allow to explore neutrino effective
masses around 40 meV.Comment: 13 pages, 19 figures. Accepted by Astroparticle Physic
Effects of new physics in neutrino oscillations in matter
A new flavor changing electron neutrino interaction with matter would always
dominate the nu_e oscillation probability at sufficiently high neutrino
energies. Being suppressed by theta_{13}, the energy scale at which the new
effect starts to be relevant may be within the reach of realistic experiments,
where the peculiar dependence of the signal with energy could give rise to a
clear signature in the nu_e --> nu_tau channel. The latter could be observed by
means of a coarse large magnetized detector by exploiting tau --> mu decays. We
discuss the possibility of identifying or constraining such effects with a high
energy neutrino factory. We also comment on the model independent limits on
them.Comment: 11 pages, 5 figure
Focal-plane detector system for the KATRIN experiment
The focal-plane detector system for the KArlsruhe TRItium Neutrino (KATRIN)
experiment consists of a multi-pixel silicon p-i-n-diode array, custom readout
electronics, two superconducting solenoid magnets, an ultra high-vacuum system,
a high-vacuum system, calibration and monitoring devices, a scintillating veto,
and a custom data-acquisition system. It is designed to detect the low-energy
electrons selected by the KATRIN main spectrometer. We describe the system and
summarize its performance after its final installation.Comment: 28 pages. Two figures revised for clarity. Final version published in
Nucl. Inst. Meth.
Gamma-induced background in the KATRIN main spectrometer
International audienceThe KArlsruhe TRItium Neutrino (KATRIN) experiment aims to make a model-independent determination of the effective electron antineutrino mass with a sensitivity of 0.2 eV/c 2 . It investigates the kinematics of β -particles from tritium β -decay close to the endpoint of the energy spectrum. Because the KATRIN main spectrometer (MS) is located above ground, muon-induced backgrounds are of particular concern. Coincidence measurements with the MS and a scintillator-based muon detector system confirmed the model of secondary electron production by cosmic-ray muons inside the MS. Correlation measurements with the same setup showed that about 12% of secondary electrons emitted from the inner surface are induced by cosmic-ray muons, with approximately one secondary electron produced for every 17 muon crossings. However, the magnetic and electrostatic shielding of the MS is able to efficiently suppress these electrons, and we find that muons are responsible for less than 17% (90% confidence level) of the overall MS background
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