66 research outputs found
Limits on different majoron decay modes of 100Mo and 82Se for neutrinoless double beta decays in the NEMO-3 experiment
The NEMO-3 tracking detector is located in the FrĂŠjus Underground Laboratory. It was designed to study double beta decay in a number of different isotopes. Presented here are the experimental half-life limits on the double beta decay process for the isotopes 100Mo and 82Se for different majoron emission modes and limits on the effective neutrinoâmajoron coupling constants. In particular, new limits on âordinaryâ majoron (spectral index 1) decay of 100Mo (T1/2>2.7Ă1022 yr) and 82Se (T1/2>1.5Ă1022 yr) have been obtained. Corresponding bounds on the majoronâneutrino coupling constant are gee<(0.4â1.8)Ă10â4 and <(0.66â1.9)Ă10â4
Effects of architectural issues on a km3 scale detector
Simulation results showing the comparison between the performance of
different km3 detector geometries are reported. Effective neutrino areas and
angular resolutions are reported for three different geometries based on
NEMO-towers and strings. The results show that the NEMO-tower based detector
has the best performance concerning both the effective area and the angular
resolution isotropyComment: to be published on VVVNT2 proceedings (Catania, Italy, November 8-11,
2005
Results from NEMO 3
The NEMO 3 experiment is located in the Modane Underground Laboratory and has
been taking data since 2003 with seven isotopes. It is searching for the double
beta decay process with two or zero neutrinos emitted in the final state.
Precision measurements of the half-life of the isotopes due to two neutrino
double beta decay have been performed and new results for 96Zr, 48Ca and 150Nd
are presented here. Measurements of this process are important for reducing the
uncertainties on the nuclear matrix elements. No evidence for zero neutrino
double beta decay has been found and a 90% Confidence Level lower limit on the
half-life of this process is derived. From this an upper limit can be set on
the effective Majorana neutrino mass using the most recent nuclear matrix
elements calculations.Comment: 4 pages, 6 figures, a paper submitted to the proceedings for the
conference Neutrino0
Measurement of the double-ss decay half-life and search for the neutrinoless double-ss decay of Ca-48 with the NEMO-3 detector
Neutrinoless double-β decay is a powerful probe of lepton number violating processes that may arise from Majorana terms in neutrino masses, or from supersymmetric, left-right symmetric, and other extensions of the Standard Model. Of the candidate isotopes for the observation of this process, 48Ca has the highest Qββ -value, resulting in decays with energies significantly above most naturally occurring backgrounds. The nucleus also lends itself to precise matrix element calculations within the nuclear shell model. We present the world's best measurement of the two-neutrino double-β decay of 48Ca, obtained by the NEMO-3 collaboration using 5.25 yr of data recorded with a 6.99 g sample of isotope, yielding â 150 events with a signal to background ratio larger than 3. Neutrinoless modes of double-β decay are also investigated, with no evidence of new physics. Furthermore, these results indicate that two-neutrino double-β decay would be the main source of background for similar future searches using 48Ca with significantly larger exposures
Inertial bioluminescence rhythms at the Capo Passero (KM3NeT-Italia) site, Central Mediterranean Sea
Peer reviewedPublisher PD
High-Energy Neutrino Astronomy
Kilometer-scale neutrino detectors such as IceCube are discovery instruments
covering nuclear and particle physics, cosmology and astronomy. Examples of
their multidisciplinary missions include the search for the particle nature of
dark matter and for additional small dimensions of space. In the end, their
conceptual design is very much anchored to the observational fact that Nature
accelerates protons and photons to energies in excess of and
eV, respectively. The cosmic ray connection sets the scale of cosmic
neutrino fluxes. In this context, we discuss the first results of the completed
AMANDA detector and the reach of its extension, IceCube. Similar experiments
are under construction in the Mediterranean. Neutrino astronomy is also
expanding in new directions with efforts to detect air showers, acoustic and
radio signals initiated by super-EeV neutrinos.Comment: 9 pages, Latex2e, uses ws-procs975x65standard.sty (included), 4
postscript figures. To appear in Proceedings of Thinking, Observing, and
Mining the Universe, Sorrento, Italy, September 200
Short Term and Long Term Bioacoustic Monitoring of the Marine Environment. Results from NEMO ONDE Experiment and Way Ahead.
The INFN NEMO-OνDE (Ocean Noise Detection Experiment) station, deployed on the seafloor at 2000 m depth 25 km offshore Catania (Sicily, Italy) in year 2005, was designed to continuously transmit broad-band acoustic data through optical cables to the INFN lab located in the port of Catania. It was operational until November 2006, when it was replaced by other experimental equipment. During the operational period, 5 minutes of recording (4 hydrophones, 45 kHz bandwidth, 96 kHz sampling rate at 24 bits resolution) were taken every hour. The experiment provided long-term data on the underwater noise and an unique opportunity to study the acoustic emissions of marine mammals living in, or transiting through the area east of Sicily. The recordings revealed a more frequent and consistent presence of sperm whales than previously believed
- âŚ