Search results for " Neutrino"
showing 10 items of 727 documents
Omnibus experiment: CPT and CP violation with sterile neutrinos
2016
We propose to probe both the CPT and CP violation together with the search for sterile neutrinos in one do-it-all experiment. This omnibus experiment would utilize neutrino oscillometry with large scintillator detectors like LENA, JUNO or RENO-50 and manmade radioactive sources similar to the ones used by the GALLEX experiment. Our calculations indicate that such an experiment is realistic and could be performed in parallel to the main research plan for JUNO, LENA, or RENO-50. Assuming as the starting point the values of the oscillation parameters indicated by the current global fit (in 3 active + 1 sterile scenario) and requiring at least 5 sigma confidence level, we estimate that with the…
Calibration campaign of the Borexino detector for the search of sterile neutrinos with SOX
2020
Abstract The SOX (Short distance Oscillations with boreXino) experiment aims to investigate possible anomalous oscillatory behaviours in neutrinos, including the existence of sterile neutrinos, by exploiting the very low radioactive background of the Borexino detector. A calibration campaign is crucial to achieve a deeper understanding of the energy response and the spatial reconstruction accuracies of the detector. It will be performed with a suite of low-activity radioactive sources which will map the whole active volume, especially nearby the inner vessel. The calibration points at the border of the active zones will be extremely important to study the neutron detection efficiency. The c…
Search for sterile neutrinos with SOX: Monte Carlo studies of the experiment sensitivity and systematic effects
2020
Abstract Some neutrino experiments reveal anomalous results which can make room for new physics beyond the three-flavor neutrino oscillation model. These hints suggest the existence of sterile neutrinos with mass m <eV. SOX will be a short-baseline disappearance experiment aiming to test this hypotesis, performed with the liquid scintillator detector Borexino at Gran Sasso National Laboratory in Italy [1]. Due to the good energy and position resolution, a light sterile neutrino can create an oscillatory pattern in the signal. The SOX sensitivity, the related analysis and systematics will be briefly discussed.
Active-active and active-sterile neutrino oscillation solutions to the atmospheric neutrino anomaly
1998
We perform a fit to the full data set corresponding to 33.3 kt-yr of data of the Super-Kamiokande experiment as well as to all other experiments in order to compare the two most likely solutions to the atmospheric neutrino anomaly in terms of oscillations in the $\nu_\mu \to \nu_\tau$ and $\nu_\mu \to \nu_s$ channels. Using state-of-the-art atmospheric neutrino fluxes we have determined the allowed regions of oscillation parameters for both channels. We find that the $\Delta m^2$ values for the active-sterile oscillations (both for positive and negative $\Delta m^2$) are higher than for the $\nu_\mu \to \nu_\tau$ case, and that the increased Super-Kamiokande sample slightly favours $\nu_\mu…
Another way of looking at the sky: Neutrino telescopes
2016
Neutrinos are weakly-interacting neutral particles, which makes them powerful sources of information about the most energetic processes in the universe, such as the origin of ultra-energetic cosmic rays or gamma-ray bursts. However, a price must be paid in order to detect them: gargantuan detectors at the bottom of the sea or under the Antarctic ice are required. The detection of the first high-energy cosmic neutrinos in 2013 by the IceCube observatory represented the start of so-called neutrino astronomy, a new way of observing the universe, which can play a key role in future discoveries. In this article, we describe how neutrino telescopes work, as well as the different initial configura…
Neutrinoless double beta decays of 106Cd revisited
2011
Abstract Neutrinoless double beta ( 0 ν 2 β ) decays of 106 Cd are studied for the transitions to the ground state, 0 gs + , and 0 + excited states in 106 Pd by using realistic many-body wave functions calculated in the framework of the quasiparticle random-phase approximation and its extensions. Effective, G-matrix-based nuclear forces are used in large single-particle model spaces. Both the β + β + and β + EC channels of the 0 ν 2 β decay are discussed and half-lives are computed. Particular attention is devoted to the study of the detectability of the resonant neutrinoless double electron capture ( R 0 ν ECEC ) process in 106 Cd. The calculations of the present article constitute the thu…
Status of neutrino oscillations 2018: 3 hint for normal mass ordering and improved CP sensitivity
2018
We present a new global fit of neutrino oscillation parameters within the simplest three-neutrino picture, including new data which appeared since our previous analysis [1]. In this update we include new long-baseline neutrino data involving the antineutrino channel in T2K, as well as new data in the neutrino channel, data from NOνA, as well as new reactor data, such as the Daya Bay 1230 days electron antineutrino disappearance spectrum data and the 1500 live days prompt spectrum from RENO, as well as new Double Chooz data. We also include atmospheric neutrino data from the IceCube DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we also update our solar oscillat…
Reactor antineutrino detection in Double Chooz experiment: Techniques for background reduction
2014
Abstract A crucial task for the Double Chooz reactor antineutrino experiment is the thorough study of the different backgrounds in the detector. Newly developed background reduction techniques minimize the impact of the backgrounds on our sensitivity. Moreover, only a precision and accuracy measurement of the residual background would allow to measure the mixing angle θ 13 with high precision. Neutrino coincidence signals are imitated by signals produced in several others physics processes: accidental coincidences of single events (accidental background), as well as correlated events induced by cosmic muons, including stopping muons, fast neutrons and spallation isotopes Li 9 /He 8 . The Do…
Neutrinoless double electron capture as a tool to measure the electron neutrino mass
1983
Abstract A nucleus (Z, A) may capture two atomic electrons to become (Z − 2, A). For Majorana neutrinos this may occur with no neutrino emission, the process is a virtual mixing of the parent atom and the daughter atom with two electron holes. The process becomes real as the daughter atom de-excites. In some cases where the daughter nucleus is excited, the neutrinoless decay may be enhanced by its proximity to a virtual resonance. We identify the 112 Sn → 112 Cd transition as a good case. The no-neutrino lifetime for mν = 30 eV ranges from 1022 to 1027 years as a function of the insufficiently well determined distance to resonance. The signatures of the two- or no-neutrino modes are very di…
Atmospheric neutrino oscillations, theta (13) and neutrino mass hierarchy
2003
We derive predictions for the Nadir angle (theta(n)) dependence of the ratio N(mu)/N(e) of the rates of the mu-like and e-like multi-GeV events measured in water-Cerenkov detectors in the case of 3-neutrino oscillations of the atmospheric nu(e) (antinu(e)) and nu(mu) (antinu(mu)), driven by one neutrino mass squared difference, |Delta m2(31)| ~ (2.5 - 3.0) x 10^(-3) eV^2 >> Delta m2(21). This ratio is particularly sensitive to the Earth matter effects in the atmospheric neutrino oscillations, and thus to the values of sin^2(theta(13)) and sin^2(theta(23)), theta(13) and theta(23) being the neutrino mixing angle limited by the CHOOZ and Palo Verde experiments and that responsible for t…