Despite the fact that the electric charge conservation law is confirmed by many experiments, search for its possible violation remains a way of searching for physics beyond the Standard Model. ...Experimental searches for the electric charge non-conservation mainly consider electron decays into neutral particles. The Borexino experiment is an excellent tool for the electron decay search due to the highest radiopurity among all the existing experiments, large detector mass, and good sensitivity at low energies. The process considered in this study is a decay into a photon and a neutrino, for which a new lower limit on the electron lifetime is obtained. This is the best electron lifetime limit up to date, exceeding the previous one obtained at the Borexino prototype at two orders of magnitude.
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.
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.
DARk matter WImp search with liquid xenoN (DARWIN) will be an experiment for the direct detection of dark matter using a multi-ton liquid xenon time projection chamber at its core. Its primary goal ...will be to explore the experimentally accessible parameter space for Weakly Interacting Massive Particles (WIMPs) in a wide mass-range, until neutrino interactions with the target become an irreducible background. The prompt scintillation light and the charge signals induced by particle interactions in the xenon will be observed by VUV sensitive, ultra-low background photosensors. Besides its excellent sensitivity to WIMPs above a mass of 5 GeV/c2, such a detector with its large mass, low-energy threshold and ultra-low background level will also be sensitive to other rare interactions. It will search for solar axions, galactic axion-like particles and the neutrinoless double-beta decay of 136-Xe, as well as measure the low-energy solar neutrino flux with <1% precision, observe coherent neutrino-nucleus interactions, and detect galactic supernovae. We present the concept of the DARWIN detector and discuss its physics reach, the main sources of backgrounds and the ongoing detector design and R&D efforts.
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.
Measurement of the Solar pp-neutrino flux completed the measurement of Solar neutrino fluxes from the pp-chain of reactions in Borexino experiment. The result is in agreement with the prediction of ...the Standard Solar Model and the MSW/LMA oscillation scenario. A comparison of the total neutrino flux from the Sun with Solar luminosity in photons provides a test of the stability of the Sun on the 105 years time scale, and sets a strong limit on the power production by the unknown energy sources in the Sun.
The detection of neutrinos emitted in the CNO reactions in the Sun is one of the ambitious goals of Borexino Phase-II. A measurement of CNO neutrinos would be a milestone in astrophysics, and would ...allow to solve serious issues in current solar models. A precise measurement of the rate of neutrinos from the pep reaction would allow to investigate neutrino oscillations in the MSW transition region. The pep and CNO solar neutrino physics, the measurement in Borexino Phase-I and the perspectives for the new phase are reviewed in this proceeding.
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