The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of ...liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10⁻⁴⁴ cm² for 55 GeV/c² WIMPs at 90% confidence level. Below 20 GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.
A systematic study of the β-decay of neutron-deficient nuclei has been carried out and has provided spectroscopic information of importance for both nuclear structure and nuclear astrophysics. ...Following an overview of the most relevant achievements, we focus on the latest results on the β decay of
60
Ge and
62
Ge. We also summarise our results on the mass excesses in comparison with systematics and a recent measurement. Finally, we present updated half-life trends for
T
z
= -1/2, -1 and -2 neutron-deficient nuclides.
Abstract
Project Meitner is an outreach initiative aiming at raising awareness on the situation of women in Physics. To this purpose, a series of actions have been carried out at the Instituto de ...Física Corpuscular (IFIC, Spain) with a double purpose: help the pioneer women of radioactivity become known by the broad public, and demystify the current archetypal view of the scientist by presenting the diversity of women who work at our institute. Special attention is paid to stimulate the self-confidence in Physics, Engineering and Computer Science (PECS) subjects to secondary-education female students, as well as to other types of public usually overlooked in outreach activities, such as people with disabilities and elderly people.
The β decays of the proton-rich, Tz = −2 nuclei 48Fe, 52Ni and 56Zn were investigated by decay spectroscopy at GANIL. The decay schemes were determined, together with absolute Fermi and Gamow-Teller ...transition strengths. New interesting results were obtained, including the first observation of a new decay mode in the f p-shell, the exotic β- delayed γ-proton decay seen in 56Zn, and the first observation of the 2+ isomer in 52Co. These studies were complemented by Charge Exchange reactions on the stable mirror targets.
Characterization and performance of the DTAS detector Guadilla, V.; Tain, J.L.; Algora, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2018, Volume:
910, Issue:
C
Journal Article
Peer reviewed
Open access
DTAS is a segmented total absorption γ-ray spectrometer developed for the DESPEC experiment at FAIR. It is composed of up to eighteen NaI(Tl) crystals. In this work we study the performance of this ...detector with laboratory sources and also under real experimental conditions. We present a procedure to reconstruct offline the sum of the energy deposited in all the crystals of the spectrometer, which is complicated by the effect of NaI(Tl) light-yield non-proportionality. The use of a system to correct for time variations of the gain in individual detector modules, based on a light pulse generator, is demonstrated. We describe also an event-based method to evaluate the summing-pileup electronic distortion in segmented spectrometers. All of this allows a careful characterization of the detector with Monte Carlo simulations that is needed to calculate the response function for the analysis of total absorption γ-ray spectroscopy data. Special attention was paid to the interaction of neutrons with the spectrometer, since they are a source of contamination in studies of β-delayed neutron emitting nuclei.
We report the observation of a very exotic decay mode at the proton drip line, the beta -delayed gamma -proton decay, clearly seen in the beta decay of the T sub(z)= -2 nucleus super(56)Zn. Three ...gamma -proton sequences have been observed after the beta decay. Here this decay mode, already observed in the sd shell, is seen for the first time in the fp shell. Both gamma and proton decays have been taken into account in the estimation of the Fermi and Gamow-Teller strengths. Evidence for fragmentation of the Fermi strength due to strong isospin mixing is found.
We present a new approach to determine the nuclear form factors which are important for the direct dark matter experiments. We perform a systematic global determination of the form factors covering a ...wide range of nuclei, from 9Be to 209Bi. The commonly-used Lewin-Smith approach is improved by fitting both parameters of the Fermi proton-density distributions directly to the experimental data. Our procedure allows to extract the widely-used Helm form factor, providing for the first time realistic (conservative) uncertainties for the parameters. In addition, we rely on recent measurements of antiprotonic atoms to constrain the neutron-density distributions. Systematics errors are estimated and possible correlations are explored.
We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow ...electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.
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