Rare event physics demands very detailed background control, high-performance detectors, and custom analysis strategies. Cryogenic calorimeters combine all these ingredients very effectively, ...representing a promising tool for next-generation experiments. CUPID-0 is one of the most advanced examples of such a technique, having demonstrated its potential with several results obtained with limited exposure. In this paper, we present a further application. Exploiting the analysis of delayed coincidence, we can identify the signals caused by the 220Rn-216Po decay sequence on an event-by-event basis. The analysis of these events allows us to extract the time differences between the two decays, leading to a new evaluation of 216Po half-life, estimated as (143.3±2.8) ms.
We operated a
PbMoO
4
scintillating cryogenic detector of 570 g, produced with archaeological lead. This compound features excellent low temperature characteristics in terms of light yield, ...12 keV/MeV for
β
/
γ
interactions, and FWHM energy resolution, 11.7 keV at 2.6 MeV. Furthermore, the detector allows for an effective particle identification by means of pulse shape analysis on the heat read-out channel. The implementation of innovative techniques and procedures for the purification of raw materials used for the crystal growth, and the highly-pure archaeological Pb, allowed for the production of large volume high-quality crystal. The overall characteristics of the detector operated at cryogenic temperatures makes
PbMoO
4
an excellent compound for neutrino physics applications, especially neutrinoless double-beta studies.
We theoretically study the levitation of a single magnetic domain nanosphere in an external static magnetic field. We show that, apart from the stability provided by the mechanical rotation of the ...nanomagnet (as in the classical Levitron), the quantum spin origin of its magnetization provides two additional mechanisms to stably levitate the system. Despite the Earnshaw theorem, such stable phases are present even in the absence of mechanical rotation. For large magnetic fields, the Larmor precession of the quantum magnetic moment stabilizes the system in full analogy with magnetic trapping of a neutral atom. For low magnetic fields, the magnetic anisotropy stabilizes the system via the Einstein–de Haas effect. These results are obtained with a linear stability analysis of a single magnetic domain rigid nanosphere with uniaxial anisotropy in a Ioffe-Pritchard magnetic field.
The 1-ton-scale CUORE detector is made of 988
TeO
2
crystals operated as cryogenic bolometers at a working temperature of
∼
10
mK
. In order to provide the necessary cooling power at 4 K stage, a ...total of five pulse tube (PT) refrigerators are used. The PTs make the cryogenic system reliable and stable, but have the downside that mechanical vibrations at low frequencies (1.4 Hz and related harmonics) are injected into the experimental apparatus. An active noise cancellation technique has been developed in order to reduce such effect by taking advantage from the coherent interference of the pressure oscillations originated by the different PTs. The technique that will be presented consists in controlling the relative phases of the pressure waves running inside the CUORE PT lines, in order to achieve the lowest detector noise. By reducing the power of PT harmonics by a factor up to
10
4
, it drastically suppresses the overall noise RMS on the CUORE detector. In the following, we demonstrate the reliability and effectiveness of the technique, showing that the optimization of the detector noise level is possible in different experimental conditions.
The production of ultra-pure raw material is a crucial step to ensure the required background level in rare event searches. In this work, we establish an innovative technique developed to produce ...high-purity (99.999%) granular zinc. We demonstrate the effectiveness of the refining procedure by measuring the internal contaminations of the purified zinc with a high-purity germanium detector at the Laboratori Nazionali del Gran Sasso. The total activity of cosmogenic activated nuclides is measured at the level of a few mBq/kg, as well as limits on naturally occurring radionuclides are set to less than mBq/kg. The excellent radiopurity of the zinc sample allows us to search for electron capture with positron emission and neutrinoless double electron capture of
64
Zn, setting the currently most stringent lower limits on their half-lives,
T
1
/
2
ε
β
+
>
2.7
×
10
21
year
(90% CI), and
T
1
/
2
0
ν
2
ε
>
2.6
×
10
21
year
(90% CI), respectively.
Patient safety and treatment outcome could be improved if physicians could rapidly control the activity of therapeutic agents in their patients. Antidote control is the safest way to regulate drug ...activity, because unlike rapidly clearing drugs, control of the drug activity is independent of underlying patient physiology and co-morbidities. Until recently, however, there was no general method to discover antidote-controlled drugs. Here we demonstrate that the activity and side effects of a specific class of drugs, called aptamers, can be controlled by matched antidotes in vivo. The drug, an anticoagulant aptamer, systemically induces anticoagulation in pigs and inhibits thrombosis in murine models. The antidote rapidly reverses anticoagulation engendered by the drug, and prevents drug-induced bleeding in surgically challenged animals. These results demonstrate that rationally designed drug-antidote pairs can be generated to provide control over drug activities in animals.
In the field of fundamental particle physics, the neutrino has become more and more important in the last few years, since the discovery of its mass. In particular, the ultimate nature of the ...neutrino (if it is a Dirac or a Majorana particle) plays a crucial role not only in neutrino physics, but also in the overall framework of fundamental particle interactions and in cosmology. The only way to disentangle its ultimate nature is to search for the neutrinoless double beta decay. The idea of LUCIFER is to combine the bolometric technique proposed for the CUORE experiment with the bolometric light detection technique used in cryogenic dark matter experiments. The bolometric technique allows an extremely good energy resolution while its combination with the scintillation detection offers an ultimate tool for background rejection. The goal of LUCIFER is not only to build a background-free small-scale experiment but also to directly prove the potentiality of this technique. Preliminary tests on several detectors containing different interesting DBD emitters have clearly demonstrated the excellent background rejection capabilities that arise from the simultaneous, independent, double readout of heat and scintillation light.
Many therapeutic agents are associated with adverse effects in patients. Anticoagulants can engender acute complications such as significant bleeding that increases patient morbidity and mortality. ...Antidote control provides the safest means to regulate drug action. For this reason, despite its known limitations and toxicities, heparin use remains high because it is the only anticoagulant that can be controlled by an antidote, the polypeptide protamine. To date, no generalizable strategy for developing drug-antidote pairs has been described. We investigated whether drug-antidote pairs could be rationally designed by taking advantage of properties inherent to nucleic acids to make antidote-controlled anticoagulant agents. Here we show that protein-binding oligonucleotides (aptamers) against coagulation factor IXa are potent anticoagulants. We also show that oligonucleotides complementary to these aptamers can act as antidotes capable of efficiently reversing the activity of these new anticoagulants in plasma from healthy volunteers and from patients who cannot tolerate heparin. This generalizable strategy for rationally designing a drug-antidote pair thus opens up the way for developing safer regulatable therapeutics.
Zinc molybdate (ZnMoO4) crystals are an excellent candidate material to fabricate scintillating bolometers for the study of neutrinoless double beta decay of 100Mo, provided that the crystal quality ...meets strict optical, thermal and radiopurity requirements. This paper addresses the characterization of improved crystalline samples grown by the low-thermal-gradient Czochralski technique. Transmittance measurements confirm significant improvement of the material with respect to previously developed samples. Luminescence properties (emission spectra, dependence of intensity on temperature, thermally stimulated luminescence and phosphorescence) have been studied under X-ray excitation from liquid-helium to room temperature. The index of refraction was measured in the wavelength interval 406–655nm. Samples of ZnMoO4 crystals with masses of 5.07g and 23.8g were operated as scintillating bolometers at temperatures below 30mK, with simultaneous detection of scintillation and heat signals, confirming an excellent alpha/beta rejection power. Background measurements allowed encouraging radiopurity level estimations. The light collection from ZnMoO4 scintillators was Monte Carlo simulated, analysing different crystal size, shape and surface properties and different photodetector sizes.
PDF
