Search results for "neutri"
showing 10 items of 1793 documents
Theoretical study of neutrino scattering off the stable even Mo isotopes at low and intermediate energies
2011
A systematic study of the cross sections of neutral-current neutrino scattering off the stable even Mo isotopes (mass number A = 92, 94, 96, 98, 100), at low and intermediate neutrino energies (E(nu) <= 130 MeV), is presented and discussed. The required wave functions for the initial (ground state) and all accessible final nuclear states are constructed in the context of the quasi-particle random-phase approximation (QRPA) and tested against data on the low-lying energy spectra of the isotopes in question. The individual contributions coming from the polar-vector and axial-vector components of the hadronic current for the coherent and incoherent channels of each isotope are investigated. Th…
Measurement of Atmospheric Neutrino Oscillations at 6–56 GeV with IceCube DeepCore
2018
We present a measurement of the atmospheric neutrino oscillation parameters using three years of data from the IceCube Neutrino Observatory. The DeepCore infill array in the center of IceCube enables the detection and reconstruction of neutrinos produced by the interaction of cosmic rays in Earth's atmosphere at energies as low as ∼5 GeV. That energy threshold permits measurements of muon neutrino disappearance, over a range of baselines up to the diameter of the Earth, probing the same range of L/Eν as long-baseline experiments but with substantially higher-energy neutrinos. This analysis uses neutrinos from the full sky with reconstructed energies from 5.6 to 56 GeV. We measure Δm322=2.31…
Recent highlights from GENIE v3
2021
Funder: u.s. department of energy; doi: http://dx.doi.org/10.13039/100000015
Measurement of the double-beta decay half-life and search for the neutrinoless double-beta decay of Ca48 with the NEMO-3 detector
2016
The NEMO-3 experiment at the Modane Underground Laboratory investigates the double-beta decay of Ca48. Using 5.25 yr of data recorded with a 6.99 g sample of Ca48, approximately 150 double-beta decay candidate events are selected with a signal-to-background ratio greater than 3. The half-life for the two-neutrino double-beta decay of Ca48 is measured to be T2ν1/2=[6.4+0.7−0.6(stat)+1.2−0.9(syst)]×1019 yr. A search for neutrinoless double-beta decay of Ca48 yields a null result, and a corresponding lower limit on the half-life is found to be T0ν1/2>2.0×1022 yr at 90% confidence level, translating into an upper limit on the effective Majorana neutrino mass of ⟨mββ⟩<6.0–26 eV, with the rang…
Neutri Ravennan papyruksissa : määrällinen ja laadullinen analyysi neutrikategorian tilasta ja muutoksesta myöhäislatinalaisessa tekstikorpuksessa
2010
Tutkielmani aineistona ovat Ravennan papyrukset, jotka on kirjoitettu vuosien 433 ja n. 750 välillä Italiassa. Näitä latinankielisiä originaaliasiakirjoja on 59 kappaletta, ja ne sisältävät yhteensä n. 19 000 sanaa. Tarkastelen kvantitatiivisin ja kvalitatiivisin menetelmin neutrin tilaa dokumenttien kielessä, joka on vahvasti asiakirjakaavan säätelemää. Menetelmäni perustuvat substantiivien taivutuspäätteiden määrien vertailuun. Pronominit ja sukunsa kongruenssin välityksellä saavat määreet on jätetty tilastoinnin ulkopuolelle. Ensisijaisesti keskityn 2. deklinaation yksiköllisen um-päätteisen neutrin maskuliinisoitumiseen ja a-päätteisen monikon feminiinisoitumiseen. Vertaan havaintojani …
Theoretical estimates of supernova-neutrino cross sections for the stable even-even lead isotopes: Charged-current reactions
2016
A detailed study of the charged-current supernova electron neutrino and electron antineutrino scattering off the stable even-mass lead isotopes A = 204, 206, and 208 is reported in this work. The proton-neutron quasiparticle random-phase approximation (pnQRPA) is adopted to construct the nuclear final and initial states. Three different Skyrme interactions are tested for their isospin and spin-isospin properties and then applied to produce (anti)neutrino-nucleus scattering cross sections for (anti)neutrino energies below 80 MeV. Realistic estimates of the nuclear responses to supernova (anti)neutrinos are computed by folding the computed cross sections with a two-parameter Fermi-Dirac distr…
Theoretical study of supernova neutrino and antineutrino scattering off the stable cadmium and lead isotopes
2017
In this thesis work, an extensive study of neutrino- and antineutrino-nucleus interactions is performed. The work is focused on supernova-neutrino scattering off the stable cadmium and lead isotopes. The studied nuclei are of interest for the investigations of neutrino-properties and for neutrino-detection experiments. The adopted nuclear-structure models are based on the quasiparticle random-phase approximation (QRPA) and the microscopic quasiparticle- phonon model (MQPM) and the cross-sections calculations are based on the Donnelly-Walecka formalism. The computed cross sections are folded with a two-parameter Fermi-Dirac distribution to obtain realistic estimates of the nuclear responses …
LeptoGen-koodi
2021
LeptoGen is a software package for numerically solving (resonant) leptogenesis equations including full flavour coherence information for the Majorana neutrinos. The package is written in Wolfram Language and can be run in the Mathematica front end. (Tested in Mathematica 12.0.) For usage license, see the attachment.
Breaking of discrete symmetries and global lepton number in neutrino physics
2019
En relación con principios de simetría, esta Tesis ha abordado una serie de preguntas abiertas fundamentales en física de neutrinos. Por un lado, la existencia de violación de CP genuina en el sector leptónico, bajo el problema histórico de la falsa violación de CP inducida por la propagación de neutrinos en materia, que también conduce a la discriminación de la jerarquía en el ordenamiento de masas de los neutrinos. Demostramos que, en cualquier transición de sabor, las asimetrías que violan CP, T y CPT en oscilaciones de neutrinos en materia pueden escribirse en términos de una base de tres componentes independientes: (a) la genuina CPT-par, no nula sii hay violación genuina de CP ; (b) l…
Searches for lepton number violation and resonances in K± → πμμ decays
2017
The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003–2004. A new upper limit on the rate of the lepton number violating decay K±→π∓μ±μ± is reported: B(K±→π∓μ±μ±)<8.6×10−11 at 90% CL. Searches for two-body resonances X in K±→πμμ decays (such as heavy neutral leptons N4 and inflatons χ ) are also presented. In the absence of signals, upper limits are set on the products of branching fractions B(K±→μ±N4)B(N4→πμ) and B(K±→π±X)B(X→μ+μ−) for ranges of assumed resonance masses and lifetimes. The limits are in the (10−11,10−9) range for resonance lifetimes below 100 ps.