Search results for "neutri"

Pallomaisen TPC-ilmaisimen ominaisuuksien tutkiminen supernovaneutriinojen havaitsemiseksi

2005

Einstein Versus Neutrinos

2013

This article focuses on the news coverage given to the CERN (European Organization for Nuclear Research) announcement that neutrinos might exceed the speed of light, flying in the face of Albert Einstein’s theory. By studying 140 cartoons about the news item published between the CERN’s announcement at the end of September 2011 up until its refutation in February 2012, we selected 33 devoted to Albert Einstein. We study the iconographic use of Einstein’s figure, and how the suggestion he might have been wrong stirred up greater interest among the cartoonists than when it was proven his ideas are still fully in force.

High-precision measurement of the mass difference between 102Pd and 102Ru

2019

Abstract The Q-value for the neutrinoless double electron capture on 102Pd, Qϵϵ(102Pd), is determined as the atomic mass difference between 102Pd and 102Ru. A precise measurement of the Qϵϵ(102Pd) at the SHIPTRAP Penning trap showed a more than 10σ deviation to the adopted Atomic Mass Evaluation (AME) value. The reliability of the SHIPTRAP measurement was challenged because the AME value was based on numerous experiments including β and electron capture decays and very precise (n, γ) data, all agreeing with each other. To solve the discrepancy, the Qϵϵ(102Pd) has now been determined with the JYFLTRAP Penning trap at the IGISOL facility in the Accelerator Laboratory of the University of Jyva…

A "DUAL" MODEL OF A MASSIVE SPIN-1/2 POINT PARTICLE, AND A THEORETICAL EXPLANATION FOR THE EFFECT OF "MAXIMAL PARITY-VIOLATION"

2006

The open question left by elementary particle physics about the origin of the so-called ``maximal parity-violation'' is dealt with. It is shown that an actual theoretical answer could be found within a new relativistic quantum field formalism being a strictly covariant fermion--antifermion extension of the usual one for massive fermions. This formalism can account naturally for the effect at issue, in such a way as even to restore both parity and charge-conjugation symmetries: it spontaneously provides a true ``chiral field'' approach, which gives rise to the conjecture of a pseudoscalar (extra) charge variety anticommuting with the scalar (ordinary) one and just underlying the ``maximally …

Theoretical predictions of wimp-nucleus and neutrino-nucleus scattering in context of dark matter direct detection

2018

The nature of dark matter is at present an open question. Assuming the main component of dark matter consists of weakly interacting massive particles (WIMPs), directly detecting such particle via a scattering process with an atomic nucleus would be a strong probe into properties of dark matter. So far direct detection experiments have not provided a conclusive signal of dark matter. Traditionally the experiments aim to detect a coherent, spin- independent, elastic scattering signal which is enhanced by the square of the nuclear mass number. If the coherent channel is for some reason suppressed for WIMP-nucleus interactions, then spin-dependent interactions become important. In this thesis w…

Mass testing and characterization of 20-inch PMTs for JUNO

2022

Main goal of the JUNO experiment is to determine the neutrino mass ordering using a 20 kt liquid-scintillator detector. Its key feature is an excellent energy resolution of at least 3% at 1 MeV, for which its instruments need to meet a certain quality and thus have to be fully characterized. More than 20,000 20-inch PMTs have been received and assessed by JUNO after a detailed testing program which began in 2017 and elapsed for about four years. Based on this mass characterization and a set of specific requirements, a good quality of all accepted PMTs could be ascertained. This paper presents the performed testing procedure with the designed testing systems as well as the statistical charac…

Extending Physics Potential of Large Liquid Scintillator Neutrino Detectors

2016

Evidence of Single State Dominance in the Two-Neutrino Double-β Decay of ^{82}Se with CUPID-0.

2019

We report on the measurement of the two-neutrino double-β decay of ^{82}Se performed for the first time with cryogenic calorimeters, in the framework of the CUPID-0 experiment. With an exposure of 9.95 kg yr of Zn^{82}Se, we determine the two-neutrino double-β decay half-life of ^{82}Se with an unprecedented precision level, T_{1/2}^{2ν}=[8.60±0.03(stat) _{-0.13}^{+0.19}(syst)]×10^{19}  yr. The very high signal-to-background ratio, along with the detailed reconstruction of the background sources allowed us to identify the single state dominance as the underlying mechanism of such a process, demonstrating that the higher state dominance hypothesis is disfavored at the level of 5.5σ.

Ultra-High Energy Neutrinos at the Pierre Auger Observatory

2013

The observation of ultrahigh energy neutrinos (UHE nu s) has become a priority in experimental astroparticle physics. UHE nu s can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going nu) or in the Earth crust (Earth-skimming nu), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and …

Excess electronic recoil events in XENON1T

2020

We report results from searches for new physics with low-energy electronic recoil data recorded with the XENON1T detector. With an exposure of 0.65 t-y and an unprecedentedly low background rate of $76\pm2$ events/(t y keV) between 1 and 30 keV, the data enables sensitive searches for solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter. An excess over known backgrounds is observed at low energies and most prominent between 2 and 3 keV. The solar axion model has a 3.4$\sigma$ significance, and a 3D 90% confidence surface is reported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboid defined by $g_{ae}<3.8 \times 10^{-12}$,…