Horacio A. Farach

CUORE: a cryogenic underground observatory for rare events

CUORE is a proposed tightly packed array of 1000 TeO2 bolometers, each being a cube 5cm on a side with a mass of 760g. The array consists of 25 vertical towers, arranged in a square of 5 towers×5 towers, each containing 10 layers of four crystals. The design of the detector is optimized for ultralow-background searches: for neutrinoless double-beta decay of 130Te (33.8% abundance), cold dark matter, solar axions, and rare nuclear decays. A preliminary experiment involving 20 crystals 3×3×6cm3 of 340g has been completed, and a single CUORE tower is being constructed as a smaller-scale experiment called CUORICINO. The expected performance and sensitivity, based on Monte Carlo simulations and extrapolations of present results, are reported.

A decommissioned LHC model magnet as an axion telescope

The 8.4 T, 10 m long transverse magnetic field of a twin aperture LHC bending magnet can be utilized as a macroscopic coherent solar axion-to-photon converter. Numerical calculations show that the integrated time of alignment with the Sun would be 33 days/yr with the magnet on a tracking table capable of

Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

5i in the vertical direction and

Physics potential and prospects for the CUORICINO and CUORE experiments

40i in the horizontal direction. The existing lower bound on the axion-to-photon coupling constant can be improved by a factor between 30 and 100 in 3 yr, i.e., g !cc [9]10~11 GeV~1 for axion masses [ 1 eV. This value falls within the existing open axion mass window. The same set-up can simultaneously search for low- and high-energy celestial axions, or axion-like particles, scanning the sky as the Earth rotates and orbits the Sun. ( 1999 Elsevier Science B.V. All rights reserved.

OXIDATIVE DAMAGE, PLASMA ANTIOXIDANT CAPACITY, AND GLUCEMIC CONTROL IN ELDERLY NIDDM PATIENTS

Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector when axions are incident at a Bragg angle with a crystalline plane. The analysis of 1.94thinspthinspkgthinspyr of data from the 1thinspthinspkg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound by an axion-photon coupling of g{sub a{gamma}{gamma}}{lt}2.7{times}10{sup {minus}9} GeV{sup {minus}1} , independent of axion mass up to {approximately}1 keV . {copyright} {ital 1998} {ital The American Physical Society }

Magnetic phase diagram of spinel spin-glasses

Abstract The Cryogenic Underground Observatory for Rare Events (CUORE) experiment projects to construct and operate an array of 1000 cryogenic thermal detectors of TeO 2 , of a mass of 760 g each, to investigate rare events physics, in particular, double beta decay and non-baryonic particle dark matter. A first step towards CUORE is CUORICINO, an array of 62 bolometers, currently being installed in the Gran Sasso Laboratory. In this paper we report the physics potential of both stages of the experiment regarding neutrinoless double beta decay of 130 Te, WIMP searches and solar axions.The CUORE experiment projects to construct and operate an array of 1000 cryogenic thermal detectors of TeO2, of a mass of 760 g each, to investigate rare events physics, in particular, double beta decay and non baryonic particle dark matter. A first step towards CUORE is CUORICINO, an array of 62 bolometers, currently being installed in the Gran Sasso Laboratory. In this paper we report the physics potential of both stages of the experiment regarding neutrinoless double beta decay of 130Te, WIMP searches and solar axions.

Theory for the direct detection of solar axions by coherent Primakoff conversion in germanium detectors

A study of oxidative damage was made in elderly noninsulin-dependent diabetes mellitus (NIDDM) patients. A statistically significant increase in glucose and fructosamine was found in fasting NIDDM patients, as well as an increase in the oxidation induced by tert-butyl hydroperoxide. The Total Reactive Antioxidant Potential (TRAP) of the plasma was much reduced (p < .02) and the uricemia was unchanged. The erythrocytes of diabetic patients show greater basal oxidation products (p < .05), and the susceptibility of the diabetic erythrocytes to oxidation injury was also shown to increase in the oxidation induced by t-BOOH (p < .05). Linear regression studies showed that TRAP was associated directly with uric acid (p < .05) and inversely with fructosamine and with glucose (p < .03 and p < .05 respectively) in patients with NIDDM, but not in the controls. The levels of fructosamine were found to be related to the basal damage of the red blood cells (direct correlation, p < .001). This study suggest an useful approach to diabetic oxidative stress for clinical settings.

New limit on the neutrinoless betabeta decay of 130Te.

The article by Villain [Z. Phys. B — Condensed Matter33, 31 (1979)] is discussed and a modified magnetic phase diagram is suggested for the spinel system (AB2O4) in which theA andB sites are partially (or completely) occupied by magnetic atoms. This diagram takes into account the antiferromagnetic exchange interactionsJAA,JBB andJAB between nearest neighbor cations of various types. Regions of paramagnetic, antiferromagnetic, ferrimagnetic and possible spin glass behaviour are indicated on the diagram.

Standardization of convention for zero field splitting parameters

Abstract It is assumed that axion-like Nambu Goldstone bosons exist and are created in the sun by Primakoff conversion of photons in the Coulomb fields of nuclei. Detection rates are calculated in germanium detectors due to the coherent conversion of axions to photons in the lattice when the incident angle fulfills the Bragg condition for a given crystalline plane. The rates are correlated with the relative positions of the sun and detector yielding a definite recognizable sub-diurnal temporal pattern. A major experiment is proposed based on a large detector array.

Results from a search for the 0 ν ββ-decay of 130 Te

We report the present results of CUORICINO, a search for neutrinoless double-beta (0nu betabeta) decay of 130Te. The detector is an array of 62 TeO2 bolometers with a total active mass of 40.7 kg. The array is cooled by a dilution refrigerator shielded from environmental radioactivity and energetic neutrons, operated at approximately 8 mK in the Gran Sasso Underground Laboratory. No evidence for (0nu betabeta) decay was found and a new lower limit, T(1/2)(0nu) > or = 1.8 x 10(24) yr (90% C.L.) is set, corresponding to [m(nu)] < or = 0.2 to 1.1 eV, depending on the theoretical nuclear matrix elements used in the analysis.