Search results for "Beta Decay"
showing 10 items of 501 documents
Recent results on Heavy-Ion induced reactions of interest for 0νββ decay
2019
An updated overview of recent results on Heavy-Ion induced reactions of interest for neutrinoless double beta decay is reported in the framework of the NUMEN project. The NUMEN idea is to study heavy-ion induced Double Charge Exchange (DCE) reactions with the aim to get information on the nuclear matrix elements for neutrinoless double beta (0νββ) decay. Moreover, to infer the neutrino average masses from the possible measurement of the half- life of 0νββ decay, the knowledge of the nuclear matrix elements is a crucial aspect. Uma visão geral atualizada dos resultados recentes sobre reações induzidas por íons pesados de interesse para o decaimento beta duplo sem neutrinos é relatada na es…
Beta-decay of light nuclei close to the proton drip-line: 40Ti and 35Ca
1998
The s-decay of40Ti and35Ca have been studied at the LISE3 spectrometer at GANIL. The decay schemes were deduced from the observed s-delayed proton and γ emission of40Ti and35Ca into the ground and first excited states of39Ca and34Ar, respectively. The Gamow-Teller strength functionB(GT) of the40Ti s-decay extracted from the s-decay branching ratios and the precisely measured40Ti half-life, provides for the first time an experimental calibration of the neutrino detection efficiency for the ICARUS solar neutrino detector.
Beta-delayed proton emission observed in new lanthanide isotopes
1984
The following new, beta-delayed proton emitters have been observed at the on-line isotope separator OASIS:120La (2.8±2s),122La (8.7±7s),123Ce (3.8±2s),141Dy (1.0±2s),141Gd, and143Dy (3.2±6s). Z-identification was achieved through observation of characteristic x-rays in coincidence with protons.
Predictive discrete dark matter model and neutrino oscillations
2012
Dark Matter stability can be achieved through a partial breaking of a flavor symmetry. In this framework we propose a type-II seesaw model where left-handed matter transforms nontrivially under the flavor group Delta(54), providing correlations between neutrino oscillation parameters, consistent with the recent Daya-Bay and RENO reactor angle measurements, as well as lower bounds for neutrinoless double beta decay. The dark matter phenomenology is provided by a Higgs-portal.
Precise measurement of $2\nu\beta\beta$ decay of $^{100}$Mo with the CUPID-Mo detection technology
2020
We report the measurement of the two-neutrino double-beta ($2\nu\beta\beta$) decay of $^{100}$Mo to the ground state of $^{100}$Ru using lithium molybdate (\crystal) scintillating bolometers. The detectors were developed for the CUPID-Mo program and operated at the EDELWEISS-III low background facility in the Modane underground laboratory. From a total exposure of $42.235$ kg$\times$d, the half-life of $^{100}$Mo is determined to be $T_{1/2}^{2\nu}=[7.12^{+0.18}_{-0.14}\,\mathrm{(stat.)}\pm0.10\,\mathrm{(syst.)}]\times10^{18}$ years. This is the most accurate determination of the $2\nu\beta\beta$ half-life of $^{100}$Mo to date. We also confirm, with the statistical significance of $>3\sigm…
Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy gamma-rays
2014
NEXT-MM is a general-purpose high pressure (10 bar, $\sim25$ l active volume) Xenon-based TPC, read out in charge mode with an 8 cm $\times$8 cm-segmented 700 cm$^2$ plane (1152 ch) of the latest microbulk-Micromegas technology. It has been recently commissioned at University of Zaragoza as part of the R&D of the NEXT $0\nu\beta\beta$ experiment, although the experiment's first stage is currently being built based on a SiPM/PMT-readout concept relying on electroluminescence. Around 2 million events were collected during the last months, stemming from the low energy $\gamma$-rays emitted by a $^{241}$Am source when interacting with the Xenon gas ($\epsilon$ = 26, 30, 59.5 keV). The localized…
Present Status and Future Perspectives of the NEXT Experiment
2014
Gómez Cadenas, Juan José et al.
Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment
2013
NEXT-DEMO is a large-scale prototype of the NEXT-100 detector, an electroluminescent time projection chamber that will search for the neutrinoless double beta decay of Xe-136 using 100-150 kg of enriched xenon gas. NEXT-DEMO was built to prove the expected performance of NEXT-100, namely, energy resolution better than 1% FWHM at 2.5MeV and event topological reconstruction. In this paper we describe the prototype and its initial results. A resolution of 1.75% FWHM at 511 keV (which extrapolates to 0.8% FWHM at 2.5 MeV) was obtained at 10 bar pressure using a gamma-ray calibration source. Also, a basic study of the event topology along the longitudinal coordinate is presented, proving that it…
Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements
2013
[EN] The "Neutrino Experiment with a Xenon Time-Projection Chamber" (NEXT) is intended to investigate the neutrinoless double beta decay of Xe-136, which requires a severe suppression of potential backgrounds. An extensive screening and material selection process is underway for NEXT since the control of the radiopurity levels of the materials to be used in the experimental set-up is a must for rare event searches. First measurements based on Glow Discharge Mass Spectrometry and gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterraneo de Canfranc (Spain) are described here. Activity results for natural radioactive chains and other common radionucl…
Statistical analysis of β decays and the effective value of gA in the proton-neutron quasiparticle random-phase approximation framework
2016
We perform a Markov chain Monte Carlo (MCMC) statistical analysis of a number of measured groundstate-to-ground-state single β+/electron-capture and β− decays in the nuclear mass range of A = 62–142. The corresponding experimental comparative half-lives (log f t values) are compared with the theoretical ones obtained by the use of the proton-neutron quasiparticle random-phase approximation (pnQRPA) with G-matrixbased effective interactions. The MCMC analysis is performed separately for 47 isobaric triplets and 28 more extended isobaric chains of nuclei to extract values and uncertainties for the effective axial-vector coupling constant gA in nuclear-structure calculations performed in the p…