Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature is still completely unknown. One major candidate is represented by weakly ...interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei in a sensitive target, producing observable low-energy (<100 keV) nuclear recoils. The DarkSide program aims at the WIPMs detection using a liquid argon time projection chamber (LAr-TPC). In this paper we quickly review the DarkSide program focusing in particular on the next generation experiment DarkSide-G2, a 3.6-ton LAr-TPC. The different detector components are described as well as the improvements needed to scale the detector from DarkSide-50 (50 kg LAr-TPC) up to DarkSide-G2. Finally, the preliminary results on background suppression and expected sensitivity are presented.
The large size and the very low radioactive background of solar neutrino detectors such as Borexino at the Gran Sasso Laboratory in Italy offer a unique opportunity to probe the existence of neutrino ...oscillations into new sterile components by means of carefully designed and well calibrated anti-neutrino and neutrino artificial sources. In this paper we briefly summarise the key elements of the SOX experiment, a program for the search of sterile neutrinos (and other short distance effects) by means of a 144Ce-144Pr anti-neutrino source and, possibly in the medium term future, with a 51Cr neutrino source.
The third phase of the Borexino experiment that's referred to as SOX is devoted to test the hypothesis of the existence of one (or more) sterile neutrinos at a short baseline (~5-10m). The ...experimental measurement will be made with artificial sources namely with a 144Ce-144Pr antineutrino source at the first stage (CeSOX) and possibly with a 51Cr neutrino source at the second one. The fixed 144Ce-144Pr sample will be placed beneath the detector in a special pit and the initial activity will be about 100 - 150 kCi. The start of data taking is scheduled for April 2018. The article gives a short description of the preparation for the first stage and shows the expected sensitivity.
The aim of the SOX experiment is to test the hypothesis of existence of light sterile neutrinos trough a short baseline experiment. Electron antineutrinos will be produced by an high activity source ...and detected in the Borexino experiment. Both an oscillometry approach and a conventional disappearance analysis will be performed and, if combined, SOX will be able to investigate most of the anomaly region at 95% c.l. This paper focuses on the improvements performed on the simulation code and on the techniques (calibrations) used to validate the results.
We report the result of a search for a day–night asymmetry in the 7Be solar neutrino interaction rate in the Borexino detector at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The measured ...asymmetry is Adn=0.001±0.012 (stat)±0.007 (syst), in agreement with the prediction of MSW-LMA solution for neutrino oscillations. This result disfavors MSW oscillations with mixing parameters in the LOW region at more than 8.5 σ. This region is, for the first time, strongly disfavored without the use of reactor anti-neutrino data and therefore the assumption of CPT symmetry. The result can also be used to constrain some neutrino oscillation scenarios involving new physics.
Recent Results from Borexino Jeschke, D; Agostini, M; Altenmüller, K ...
Journal of physics. Conference series,
01/2017, Letnik:
798, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Borexino experiment is taking data since 2007 at the Laboratori Nazionali del Gran Sasso in Italy accomplishing outstanding achievements in the field of neutrino physics. Its success is strongly ...based on the unprecedented ultra-high radio-purity of the inner scintillator core. The main features of the detector and the impressive results for solar and geo-neutrinos obtained by Borexino so far are summarized. The main focus is laid on the most recent results, i.e. the first real-time measurement of the solar pp neutrino flux and the detection of the signal induced by geo-neutrinos with a significance as high as 5.9σ. The measurement of the pp neutrino flux represents a direct probe of the major mechanism of energy production in the Sun and its observation at a significance of 10σ proves the stability of the Sun over a time of at least 105 years. It further puts Borexino in the unique position of being capable to test the MSW-LMA paradigm across the whole solar energy range. The geo-neutrino data allow to infer information concerning important geophysical properties of the Earth that are also discussed. The perspectives of the final stage of the Borexino solar neutrino program that are centered on the goal of measuring the CNO neutrinos that so far escaped any observation are outlined.
The Borexino detector has convincingly shown its outstanding performances in the low energy regime through its accomplishments in the observation and study of the solar and geo neutrinos. It is then ...an ideal tool to perform a state of the art source-based experiment for testing the longstanding hypothesis of a fourth sterile neutrino with ~ eV2 mass, as suggested by several anomalies accumulated over the past three decades in source, reactor, and accelerator-based experiments. The SOX project aims at successively deploying two intense radioactive sources, made of Cerium (antineutrino) and Chromium (neutrino), respectively, in a dedicated pit located beneath the detector. The existence of such an ~ eV2 sterile neutrino would then show up as an unambiguous spatial and energy distortion in the count rate of neutrinos interacting within the active detector volume. This article reports on the latest developments about the first phase of the SOX experiment, namely CeSOX, and gives a realistic projection of CeSOX sensitivity to light sterile neutrinos in a simple (3+1) model.
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