Search results for "neutriino"
showing 10 items of 83 documents
Observation of an ultralow-Q-value electron-capture channel decaying to 75As via a high-precision mass measurement
2022
A precise determination of the atomic mass of 75As has been performed utilizing the double Penning trap mass spectrometer, JYFLTRAP. The mass excess is measured to be −73035.519(42)keV/c2, which is a factor of 21 more precise and 1.3(9)keV/c2 lower than the adopted value in the newest Atomic Mass Evaluation (AME2020). This value has been used to determine the ground-state–to–ground-state electron-capture decay Q value of 75Se and β− decay Q value of 75Ge, which are derived to be 866.041(81) keV and 1178.561(65) keV, respectively. Using the nuclear energy-level data of 860.00(40) keV, 865.40(50) keV (final states of electron capture), and 1172.00(60) keV (final state of β− decay) for the exc…
Neutriinojen ja kvarkkien sekoitusmatriisien välinen yhteys
2012
In this thesis relations between neutrino mixing matrix and quark mixing matrix are studied. The focus of the analysis is on two simple cases. In the first case it is assumed that the left matrix that diagonalizes the mass matrix of charged leptons and the corresponding matrix of down quarks are equal. In the second case it is likewise assumed that the corresponding diagonalizing matrices of neutrinos and up quarks are equal. First, theoretical concepts related to the mixing of quarks and especially to the mixing of neutrinos are presented. These are e.g. fermion mass generation in the Standard Model, Majorana masses of neutrinos and the so-called seesaw mechanism. Regarding experiments, ne…
Long-baseline neutrino oscillation physics potential of the DUNE experiment
2020
The sensitivity of the Deep Underground Neutrino Experiment (DUNE) to neutrino oscillation is determined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and parameterized analysis of the near detector. Detailed uncertainties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5σσ, for all δCPδCP values, after 2 years of running with the nominal detector design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σσ (5σσ) after an exposure of 5 (10) years, for 50% o…
Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment
2022
The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE’s sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-calendar years (kt-MW-CY), where calendar years include an assumption of 57% accelerator uptime based on past accelerator performance at Fermilab. The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 4…
Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC
2022
DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 × 6 × 6 m3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons…
Kvasidegeneroituneiden steriilien neutriinojen havaitseminen
2013
We study a model of sterile neutrinos where the three ordinary active neutrinos actually consist of a superposition of an active and a sterile neutrinos forming quasidegenerate pairs. Oscillation between these pairs causes mixing between active and sterile neutrinos. Eigenmasses of the quasidegenerate pairs are very close to each other and theirs mass squared difference is of the order δm2 ~ 10^-12 eV2 or less. Such a small mass squared difference could be probed with AGN and GRB neutrinos detected in cubic kilometer size neutrino observatories. In this work, affects of different parameters and different flavours at the source to the neutrino fluxes in cases of one, two and three sterile ne…
Large Impact of the Decay of Niobium Isomers on the Reactor ¯νe Summation Calculations
2019
Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions of 100gs;100mNb and 102gs;102mNb β decays have been determined using the total absorption γ-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyväskylä. Here, the double Penning trap system JYFLTRAP was employed to disentangle the β decay of the isomeric states. The new data obtained in this …
Simulations of CERN to Pyhasalmi Neutrino Experiments with GLoBES
2014
Pitkän kantaman neutriino-oskillaatiotutkimus on siirtymässä uuteen aikaan tehokkaampien neutriinosuihkujen myötä. Viimeisimmät analyysit erilaisien neutriinokokeiden mittaustuloksista ovat rajanneet kolmen neutriinon järjestelmän oskillaatioita kuvaavan PMNS - matriisin parametriarvioita entistäkin tarkemmiksi, ja jopa θ13 > 0 -tulos on ensi kertaa todennettu reaktoridatasta. Kehitteillä olevien neutriinosuihkujen tavoitteena on saavuttaa tulevaisuudessa usean GeV:n energian mahdollistaen aiemmin ratkaisemattomien kysymysten kuten massahierarkiaongelman ja mahdollisen CP-symmetriarikon tutki- misen. Tässä tutkielmassa keskitytään LAGUNA-LBNO -hankkeessa esitettyjen LENA ja GLACIER -detekto…
Direct measurement of the mass difference of 72As-72Ge rules out 72As as a promising β-decay candidate to determine the neutrino mass
2021
Preprint of paper published on Physical Review C We report the first direct determination of the ground-state to ground-state electron-capture Q-value for the 72As to 72Ge decay by measuring their atomic mass difference utilizing the double Penning trap mass spectrometer, JYFLTRAP. The Q-value was measured to be 4343.596(75) keV, which is more than a 50-fold improvement in precision compared to the value in the most recent Atomic Mass Evaluation 2020. Furthermore, the new Qvalue was found to be 12.4(40) keV (3.1 σ) lower. With the significant reduction of the uncertainty of the ground-state to ground-state Q-value value combined with the level scheme of 72Ge from γ-ray spectro…
Nuclear matrix elements for neutrinoless ββ decays and spin-dipole giant resonances
2022
Nuclear matrix element (NME) for neutrinoless ββ decay (DBD) is required for studying neutrino physics beyond the standard model by using DBD. Experimental information on nuclear excitation and decay associated with DBD is crucial for theoretical calculations of the DBD-NME. The spin-dipole (SD) NME for DBD via the intermediate SD state is one of the major components of the DBD-NME. The experimental SD giant-resonance energy and the SD strength in the intermediate nucleus are shown for the first time to be closely related to the DBD-NME and are used for studying the spin-isospin correlation and the quenching of the axial-vector coupling, which are involved in the NME. So they are used to he…