646 research outputs found
Immune sensing of nucleic acids in inflammatory skin diseases.
Endosomal and cytosolic nucleic acid receptors are important immune sensors required for the detection of infecting or replicating viruses. The intracellular location of these receptors allows viral recognition and, at the same time, avoids unnecessary immune activation to self-nucleic acids that are continuously released by dying host cells. Recent evidence, however, indicates that endogenous factors such as anti-microbial peptides have the ability to break this protective mechanism. Here, we discuss these factors and illustrate how they drive inflammatory responses by promoting immune recognition of self-nucleic acids in skin wounds and inflammatory skin diseases such as psoriasis and lupus
Signal and noise simulation of CUORE bolometric detectors
Bolometric detectors are used in particle physics experiments to search for
rare processes, such as neutrinoless double beta decay and dark matter
interactions. By operating at cryogenic temperatures, they are able to detect
particle energies from a few keV up to several MeV, measuring the temperature
rise produced by the energy released. This work focusses on the bolometers of
the CUORE experiment, which are made of TeO crystals. The response of these
detectors is nonlinear with energy and changes with the operating temperature.
The noise depends on the working conditions and significantly affects the
energy resolution and the detection performances at low energies. We present a
software tool to simulate signal and noise of CUORE-like bolometers, including
effects generated by operating temperature drifts, nonlinearities and pileups.
The simulations agree well with data.Comment: Fixed a typo. Two small changes in the text at page
TeO bolometers with Cherenkov signal tagging: towards next-generation neutrinoless double beta decay experiments
CUORE, an array of 988 TeO bolometers, is about to be one of the most
sensitive experiments searching for neutrinoless double-beta decay. Its
sensitivity could be further improved by removing the background from
radioactivity. A few years ago it has been pointed out that the signal from
s can be tagged by detecting the emitted Cherenkov light, which is not
produced by s. In this paper we confirm this possibility. For the first
time we measured the Cherenkov light emitted by a CUORE crystal, and found it
to be 100 eV at the -value of the decay. To completely reject the
background, we compute that one needs light detectors with baseline noise below
20 eV RMS, a value which is 3-4 times smaller than the average noise of the
bolometric light detectors we are using. We point out that an improved light
detector technology must be developed to obtain TeO bolometric experiments
able to probe the inverted hierarchy of neutrino masses.Comment: 5 pages, 4 figures. Added referee correction
New experimental limits on the alpha decays of lead isotopes
For the first time a PbWO4 crystal was grown using ancient Roman lead and it
was run as a cryogenic detector. Thanks to the simultaneous and independent
read-out of heat and scintillation light, the detector was able to discriminate
beta/gamma interactions with respect to alpha particles down to low energies.
New more stringent limits on the alpha decays of the lead isotopes are
presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was
evaluated for the alpha decay of 204Pb to 200Hg
Discovery of the Eu decay
We report on the first compelling observation of decay of Eu
to the ground state of Pm. The measurement was performed using a 6.15 g
LiEu(BO) crystal operated as a scintillating bolometer. The Q-value
and half-life measured are: Q = 1948.9 keV, and
T y . The
half-life prediction of nuclear theory using the Coulomb and proximity
potential model are in good agreement with this experimental result
Development of a Li2MoO4 scintillating bolometer for low background physics
We present the performance of a 33 g Li2MoO4 crystal working as a
scintillating bolometer. The crystal was tested for more than 400 h in a
dilution refrigerator installed in the underground laboratory of Laboratori
Nazionali del Gran Sasso (Italy). This compound shows promising features in the
frame of neutron detection, dark matter search (solar axions) and neutrinoless
double-beta decay physics. Low temperature scintillating properties were
investigated by means of different alpha, beta/gamma and neutron sources, and
for the first time the Light Yield for different types of interacting particle
is estimated. The detector shows great ability of tagging fast neutron
interactions and high intrinsic radiopurity levels (< 90 \muBq/kg for 238-U and
< 110 \muBq/kg for 232-Th).Comment: revised versio
First bolometric measurement of the two neutrino double beta decay of Mo with a ZnMoO crystals array
The large statistics collected during the operation of a ZnMoO array, for
a total exposure of 1.3 kg day of Mo, allowed the first
bolometric observation of the two neutrino double beta decay of Mo. The
observed spectrum of each crystal was reconstructed taking into account the
different background contributions due to environmental radioactivity and
internal contamination. The analysis of coincidences between the crystals
allowed the assignment of constraints to the intensity of the different
background sources, resulting in a reconstruction of the measured spectrum down
to an energy of 300 keV. The half-life extracted from the data is
T= [7.15 0.37 (stat) 0.66 (syst)] 10
y.Comment: 6 pages, 2 figure, Accepted for publication in Journal of Physics G:
Nuclear and Particle Physic
Discrimination of alpha and beta/gamma interactions in a TeO bolometer
TeO crystals have proven to be superb bolometers for the search of
neutrinoless double beta decay in many respects. However, if used alone, they
do not exhibit any feature that allows to discriminate an alpha energy deposit
from a beta/gamma one. This fact limits their ability to reject the background
due to natural radioactivity and eventually affects the sensitivity of the
search. In this paper we show the results of a TeO crystal where, in
coincidence with its bolometric heat signal, also the luminescence light
escaping the crystal is recorded. The results show that we are able to measure
the light produced by beta/gamma particles, which can be explained as due to
Cerenkov emission. No light is detected from alpha particles, allowing the
rejection of this background source.Comment: 5 pages, 6 figure
Particle discrimination in TeO2 bolometers
TeO2 crystals are used as bolometric detectors in experiments searching for the neutrinoless double beta decay. The extreme rarity of the studied signal requires an ultra low background level. The natural radioactivity of the materials represents for these experiments the main background source, in particular the component due to α particles. In this work, we present a possibility for particle discrimination in TeO2 bolometers using the ËCerenkov radiation. The results show that we are able to measure the light produced by ÎČ/Îł particles, which can be explained as due to ËCerenkov emission. No light is detected from α particles, allowing the rejection of this background source
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