96 research outputs found
Bohr Phenomena for Laplace-Beltrami Operators
Cataloged from PDF version of article.We investigate a Bohr phenomenon on the spaces of solutions of weighted Laplace-Beltrami operators associated with the hyperbolic metric of the unit ball in ℂN. These solutions do not satisfy the usual maximum principle, and the spaces have natural bases none of whose members is a constant function. We show that these bases exhibit a Bohr phenomenon, define a Bohr radius for them that extends the classical Bohr radius, and compute it exactly. We also compute the classical Bohr radius of the invariant harmonic functions on the real hyperbolic space. © 2006 Royal Netherlands Academy of Arts and Sciences
Theia: an advanced optical neutrino detector
New developments in liquid scintillators, high-efficiency, fast photon detectors, and chromatic photon sorting have opened up the possibility for building a large-scale detector that can discriminate between Cherenkov and scintillation signals. Such a detector could reconstruct particle direction and species using Cherenkov light while also having the excellent energy resolution and low threshold of a scintillator detector. Situated deep underground, and utilizing new techniques in computing and reconstruction, this detector could achieve unprecedented levels of background rejection, enabling a rich physics program spanning topics in nuclear, high-energy, and astrophysics, and across a dynamic range from hundreds of keV to many GeV. The scientific program would include observations of low- and high-energy solar neutrinos, determination of neutrino mass ordering and measurement of the neutrino CP-violating phase δ, observations of diffuse supernova neutrinos and neutrinos from a supernova burst, sensitive searches for nucleon decay and, ultimately, a search for neutrinoless double beta decay, with sensitivity reaching the normal ordering regime of neutrino mass phase space. This paper describes Theia, a detector design that incorporates these new technologies in a practical and affordable way to accomplish the science goals described above
Evidence of antineutrinos from distant reactors using pure water at SNO
The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240 km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5σ
Measurement of the 8B solar neutrino flux in SNO+ with very low backgrounds
A measurement of the 8B solar neutrino flux has been made using a 69.2 kt-day dataset acquired with the SNO+ detector during its water commissioning phase. At energies above 6 MeV the dataset is an extremely pure sample of solar neutrino elastic scattering events, owing primarily to the detector’s deep location, allowing an accurate measurement with relatively little exposure. In that energy region the best fit background rate is 0.25+0.09−0.07  events/kt−day, significantly lower than the measured solar neutrino event rate in that energy range, which is 1.03+0.13−0.12  events/kt−day. Also using data below this threshold, down to 5 MeV, fits of the solar neutrino event direction yielded an observed flux of 2.53+0.31−0.28(stat)+0.13−0.10(syst)×106  cm−2 s−1, assuming no neutrino oscillations. This rate is consistent with matter enhanced neutrino oscillations and measurements from other experiments
Improved search for invisible modes of nucleon decay in water with the SNO+ detector
This paper reports results from a search for single and multi-nucleon
disappearance from the O nucleus in water within the \snoplus{} detector
using all of the available data. These so-called "invisible" decays do not
directly deposit energy within the detector but are instead detected through
their subsequent nuclear de-excitation and gamma-ray emission. New limits are
given for the partial lifetimes:
years, years, years,
years, and years at 90\% Bayesian
credibility level (with a prior uniform in rate). All but the () results improve on existing limits by a factor of about 3.info:eu-repo/semantics/publishedVersio
Measurement of neutron-proton capture in the SNO+ water phase
The SNO+ experiment collected data as a low-threshold water Cherenkov
detector from September 2017 to July 2019. Measurements of the 2.2-MeV
produced by neutron capture on hydrogen have been made using an Am-Be
calibration source, for which a large fraction of emitted neutrons are produced
simultaneously with a 4.4-MeV . Analysis of the delayed coincidence
between the 4.4-MeV and the 2.2-MeV capture revealed a
neutron detection efficiency that is centered around 50% and varies at the
level of 1% across the inner region of the detector, which to our knowledge is
the highest efficiency achieved among pure water Cherenkov detectors. In
addition, the neutron capture time constant was measured and converted to a
thermal neutron-proton capture cross section of mb
Observation of Antineutrinos from Distant Reactors using Pure Water at SNO+
The SNO+ collaboration reports the first observation of reactor antineutrinos
in a Cherenkov detector. The nearest nuclear reactors are located 240 km away
in Ontario, Canada. This analysis used events with energies lower than in any
previous analysis with a large water Cherenkov detector. Two analytical methods
were used to distinguish reactor antineutrinos from background events in 190
days of data and yielded consistent observations of antineutrinos with a
combined significance of 3.5 .Comment: v2: add missing author, add link to supplemental materia
Intra-peritoneal administration of Ecballium elaterium diminishes postoperative adhesions
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