Search results for "DOUBLE-BETA DECAY"
showing 10 items of 32 documents
Long-lived particles at the energy frontier: the MATHUSLA physics case
2019
We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of Standard Model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the $\mu$m scale up to the Big Bang Nucleosynthesis limit of $\sim 10^7$m. Neutral LLPs with lifetimes above $\sim$ 100m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging …
Ionization and scintillation response of high-pressure xenon gas to alpha particles
2013
High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the ionization and scintillation detection properties of xenon gas at 10 bar pressure. For this purpose, we use a source of alpha particles in the NEXT-DEMO time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. We measure the ionization electron drift velocity and longitudinal diffusion, and compare our results to expectations based on available electron scattering cross sections on pure xenon. In addition, two types of measurements add…
New Results from the NUMEN Project
2018
International audience; NUMEN aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of the cross sections of Heavy Ion (HI) induced Double Charge Exchange (DCE) reactions. First evidence about the possibility to get quantitative information about NME from experiments is found for the (^18O,^18Ne) and (^20Ne,^20O) reactions. Moreover, to infer the neutrino average masses from the possible measurement of the half-life of 0νββ decay, the knowledge of the NME is a crucial aspect. The key tools for this project are the high resolution Superconducting Cyclotron beam…
Informe de las prácticas externas: Calibración de SiPM del plano de trazas del detector NEXT1-EL
2011
El objetivo de las prácticas externas realizadas en el Laboratorio de Reacciones Nucleares (IFIC) es familiarizarse con los sistemas de adquisición de datos de una cámara de Xenon gaseoso a alta presión (TPC), que es el elemento principal del experimento NEXT1-EL. Esta TPC es un prototipo de otra mayor que se instalará en el Laboratorio Subterráneo de Canfranc. En concreto, mis prácticas se han centrado en la caracterización y cálculo de ganancia de fotomultiplicadores de silicio (SiPM), detectores que se emplean en el plano de tracking de la TPC para visualizar la traza de las partículas ionizantes para poder hacer una selección topológica de los eventos de interés, candidatos a ser una de…
Latest results from CUPID-0
2022
International audience; CUPID-0 is a pilot experiment in scintillating cryogenic calorimetry for the search of neutrino-less double beta decay. 26 ZnSe crystals were operated continuously in the first project phase (March 2017 - December 2018), demonstrating unprecedented low levels of background in the region of interest at the Q-value of $^{82}\rm{Se}$. From this successful experience comes a demonstration of full alpha to beta/gamma background separation, the most stringent limits on the $^{82}\rm{Se}$ neutrino-less double beta decay, as well as the most precise measurement of the $^{82}$Se half-life. After a detector upgrade, CUPID-0 began its second and last phase (June 2019 - February…
Experimental study of $^{100}$Tc $\beta$ decay with total absorption $\gamma$-ray spectroscopy
2017
International audience; The β decay of Tc100 has been studied by using the total absorption γ-ray spectroscopy technique at the Ion Guide Isotope Separator On-Line facility in Jyväskylä. In this work the new Decay Total Absorption γ-ray Spectrometer in coincidence with a cylindrical plastic β detector has been employed. The β intensity to the ground state obtained from the analysis is in good agreement with previous high-resolution measurements. However, differences in the feeding to the first-excited state as well as weak feeding to a new level at high excitation energy have been deduced from this experiment. Theoretical calculations performed in the quasiparticle random-phase approximatio…
Double-β decay within a consistent deformed approach
2015
In this paper we present a timely application of the proton-neutron deformed quasiparticle random-phase approximation (pn-dQRPA), designed to describe in a consistent way the 1+ Gamow-Teller states in oddodd deformed nuclei. For this purpose we apply a projection before variation procedure by using a singleparticle basis with projected angular momentum, provided by the diagonalization of a spherical mean field plus quadrupole-quadrupole interaction. The residual Hamiltonian contains pairing plus proton-neutron dipole terms in particle-hole and particle-particle channels, with constant strengths. As an example we describe the two-neutrino double-beta (2νββ) decay of 150Nd to the ground state…
Measurement of the 2νββ decay half-life and search for the 0νββ decay of 116Cd with the NEMO-3 detector
2017
The NEMO-3 experiment measured the half-life of the 2νββ decay and searched for the 0νββ decay of 116Cd. Using 410 g of 116Cd installed in the detector with an exposure of 5.26 y, (4968±74) events corresponding to the 2νββ decay of 116Cd to the ground state of 116Sn have been observed with a signal to background ratio of about 12. The half-life of the 2νββ decay has been measured to be T2ν1/2=[2.74±0.04(stat)±0.18(syst)]×1019 y. No events have been observed above the expected background while searching for 0νββ decay. The corresponding limit on the half-life is determined to be T0ν1/2≥1.0×1023 y at the 90% C.L. which corresponds to an upper limit on the effective Majorana neutrino mass of…
Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay
2017
Neutrinoless double beta decay (0v\b{eta}\b{eta}) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research "beyond Standard Model" and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0v\b{eta}\b{eta} decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extr…
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…