426 research outputs found
Neutrino flavour relaxation or neutrino oscillations?
We propose the new mechanism of neutrino flavour relaxation to explain the
experimentally observed changes of initial neutrino flavour fluxes. The test of
neutrino relaxation hypothesis is presented, using the data of modern reactor,
solar and accelerator experiments. The final choice between the standard
neutrino oscillations and the proposed neutrino flavour relaxation model can be
done in future experiments
Antineutrino-Deuteron Experiment at Krasnoyrsk
This report is represented the results of some experiments, which carried out
at the neutrino underground laboratory of Kranoyarsk nuclear plant.Comment: 8 pages, 3 figure
Search for electron antineutrino interactions with the Borexino Counting Test Facility at Gran Sasso
Electron antineutrino interactions above the inverse beta decay energy of
protons (E_\bar{\nu}_e>1.8) where looked for with the Borexino Counting Test
Facility (CTF). One candidate event survived after rejection of background,
which included muon-induced neutrons and random coincidences. An upper limit on
the solar flux, assumed having the B solar neutrino energy
spectrum, of 1.1 cm~s (90% C.L.) was set with a 7.8
ton year exposure. This upper limit corresponds to a solar neutrino
transition probability, , of 0.02 (90% C.L.).
Predictions for antineutrino detection with Borexino, including geoneutrinos,
are discussed on the basis of background measurements performed with the CTF.Comment: 10 pages, 9 figures, 5 table
Results from the first use of low radioactivity argon in a dark matter search
Liquid argon is a bright scintillator with potent particle identification
properties, making it an attractive target for direct-detection dark matter
searches. The DarkSide-50 dark matter search here reports the first WIMP search
results obtained using a target of low-radioactivity argon. DarkSide-50 is a
dark matter detector, using two-phase liquid argon time projection chamber,
located at the Laboratori Nazionali del Gran Sasso. The underground argon is
shown to contain Ar-39 at a level reduced by a factor (1.4 +- 0.2) x 10^3
relative to atmospheric argon. We report a background-free null result from
(2616 +- 43) kg d of data, accumulated over 70.9 live-days. When combined with
our previous search using an atmospheric argon, the 90 % C.L. upper limit on
the WIMP-nucleon spin-independent cross section based on zero events found in
the WIMP search regions, is 2.0 x 10^-44 cm^2 (8.6 x 10^-44 cm^2, 8.0 x 10^-43
cm^2) for a WIMP mass of 100 GeV/c^2 (1 TeV/c^2 , 10 TeV/c^2).Comment: Accepted by Phys. Rev.
New limits on heavy sterile neutrino mixing in -decay obtained with the Borexino detector
If heavy neutrinos with mass 2 are produced in the
Sun via the decay in a side
branch of pp-chain, they would undergo the observable decay into an electron, a
positron and a light neutrino . In the
present work Borexino data are used to set a bound on the existence of such
decays. We constrain the mixing of a heavy neutrino with mass 1.5 MeV 14 MeV to be
respectively. These are tighter limits on the mixing parameters than obtained
in previous experiments at nuclear reactors and accelerators.Comment: 7 pages, 6 figure
Recommended from our members
Spectroscopy of geo-neutrinos from 2056 days of Borexino data
We report an improved geo-neutrino measurement with Borexino from 2056 days
of data taking. The present exposure is
protonyr. Assuming a chondritic Th/U mass ratio of 3.9, we obtain geo-neutrino events. The null
observation of geo-neutrinos with Borexino alone has a probability of (5.9). A geo-neutrino signal from the mantle is
obtained at 98\% C.L. The radiogenic heat production for U and Th from the
present best-fit result is restricted to the range 23-36 TW, taking into
account the uncertainty on the distribution of heat producing elements inside
the Earth.Comment: 4 pages, 4 figure
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