670 research outputs found
Mildly mixed coupled models vs. WMAP7 data
Mildly mixed coupled models include massive neutrinos and CDM--DE coupling.
We present new tests of their likelihood vs. recent data including WMAP7,
confirming it to exceed LCDM, although at ~2\sigma's. We then show the impact
on the physics of the dark components of neutrino mass detection in tritium
beta decay or neutrinoless double beta decay experiments.Comment: Proceedings of NOW2010, Conca Specchiulla, Italy, September 4-11,
201
Constraints from Neutrinoless Double Beta Decay
We examine the constraints from the recent HEIDELBERG-MOSCOW double beta
decay experiment. It leads us to the almost degenerate or inverse hierarchy
neutrino mass scenario. In this scenario, we obtain possible upper bounds for
the Majorana CP violating phase in the lepton sector by incorporating the data
from the neutrino oscillation, the single beta decay experiments, and from the
astrophysical observation. We also predict the neutrino mass that may be
measurable in the future beta decay experiments.Comment: 10 pages, 3 figure
Real-time digital signal processor implementation of self-calibrating pulse-shape discriminator for high purity germanium
Pulse-shape analysis of the ionization signals from germanium gamma-ray
spectrometers is a method for obtaining information that can characterize an
event beyond just the total energy deposited in the crystal. However, as
typically employed, this method is data-intensive requiring the digitization,
transfer, and recording of electronic signals from the spectrometer. A hardware
realization of a real-time digital signal processor for implementing a
parametric pulse shape is presented. Specifically, a previously developed
method for distinguishing between single-site and multi-site gamma-ray
interactions is demonstrated in an on-line digital signal processor, compared
with the original off-line pulse-shape analysis routine, and shown to have no
significant difference. Reduction of the amount of the recorded information per
event is shown to translate into higher duty-cycle data acquisition rates while
retaining the benefits of additional event characterization from pulse-shape
analysis.Comment: Accepted by NIM
Measurement of the 214Bi spectrum in the energy region around the Q-value of 76Ge neutrinoless double-beta decay
In this work we present the results obtained measuring the 214Bi spectrum
from a 226Ra source with a high purity germanium detector. Our attention was
mostly focused on the energy region around the Q-value of 76Ge neutrinoless
double-beta decay (2039.006 keV). The results of this measurement are strongly
related to the first indication for the neutrinoless double beta decay of 76Ge,
given by a recent analysis \cite{Evidence,KK02-PN,KK02-Found,KK-BigArt02} of
the data collected during ten years of measurements from the HEIDELBERG-MOSCOW
experiment.Comment: 10 pages, latex2e, 5 figures, see also Home Page of HEIDELBERG
Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc
A CoGeNT confirmation of the DAMA signal
The CoGeNT collaboration has recently reported a rising low energy spectrum
in their ultra low noise germanium detector. This is particularly interesting
as the energy range probed by CoGeNT overlaps with the energy region in which
DAMA has observed their annual modulation signal. We show that the mirror dark
matter candidate can simultaneously explain both the DAMA annual modulation
signal and the rising low energy spectrum observed by CoGeNT. This constitutes
a model dependent confirmation of the DAMA signal and adds weight to the mirror
dark matter paradigm.Comment: About 8 pages, expanded and update
Theory and Phenomenology of Neutrino Mixing
We review some fundamental aspects of the theory of neutrino masses and
mixing. The results of neutrino oscillation experiments are interpreted as
evidence of three-neutrino mixing. Implications for the mixing parameters and
the neutrino masses are discussed, with emphasis on the connection with the
measurements of the absolute values of neutrino masses in beta decay and
neutrinoless double-beta decay experiments and cosmological observations.Comment: 16 pages; talks presented at Tau06 (19-22 September 2006, Pisa,
Italy) and HQL06 (16-20 October 2006, Munich, Germany
The Neutrinoless Double Beta Decay: The Case for Germanium Detectors
An overview of the current status of Neutrinoless Double Beta Decay is
presented, emphasizing on the case of Germanium Detectors.Comment: 5 figures, Invited contribution at the XXX International Meeting on
Fundamental Physics, IMFP2002, February 2002, Jaca, Spain. To appear in Nucl.
Phys. B (Proc. Suppl
Pulse Shape Discrimination in the IGEX Experiment
The IGEX experiment has been operating enriched germanium detectors in the
Canfranc Underground Laboratory (Spain) in a search for the neutrinoless double
decay of 76Ge. The implementation of Pulse Shape Discrimination techniques to
reduce the radioactive background is described in detail. This analysis has
been applied to a fraction of the IGEX data, leading to a rejection of ~60 % of
their background, in the region of interest (from 2 to 2.5 MeV), down to ~0.09
c/(keV kg y).Comment: 18 pages, 10 figure
- …
