Search results for "Exotic"
showing 10 items of 134 documents
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…
Search for weakly decaying b -flavored pentaquarks
2018
Investigations of the existence of pentaquark states containing a single $b$ (anti)quark decaying weakly into four specific final states J/$\psi K^+\pi^- p$, J/$\psi K^- \pi^- p$, J/$\psi K^- \pi^+ p$, and $J/\psi \phi (1020) p$ are reported. The data sample corresponds to an integrated luminosity of 3.0/fb in 7 and 8 TeV pp collisions acquired with the LHCb detector. Signals are not observed and upper limits are set on the product of the production cross section times branching fraction with respect to that of the $\Lambda_b$.
Tree invasions in Italian forests
2022
Many forest tree species have been moved outside their native range to provide goods and services elsewhere, but some of them have become invasive, causing negative impacts on biodiversity and human activities. The assessment and knowledge on the degree and scale to which forest ecosystems are invaded by non-native trees is of paramount importance for tailored policies and strategies aiming at forest conservation. By analyzing main databases and literature and applying a four-level scale of invasion (not currently invaded and with low invasibility; potentially invasible; moderately invaded; massively invaded), we assessed the current and potential occurrence of twenty-five invasive non-nati…
Efficient, high-resolution resonance laser ionization spectroscopy using weak transitions to long-lived excited states
2017
Laser spectroscopic studies on minute samples of exotic radioactive nuclei require very efficient experimental techniques. In addition, high resolving powers are required to allow extraction of nuclear structure information. Here we demonstrate that by using weak atomic transitions, resonance laser ionization spectroscopy is achieved with the required high efficiency (1%–10%) and precision (linewidths of tens of MHz). We illustrate experimentally and through the use of simulations how the narrow experimental linewidths are achieved and how distorted resonance ionization spectroscopy line shapes can be avoided. The role of the delay of the ionization laser pulse with respect to the excitatio…
Shape evolution in even-even N≤126, Z≥82 nuclei
2010
The shape evolution in the neutron-de cient lead, polonium and radium nuclei has been investigated via in-beam and delayed y-ray and conversion electron spectroscopy. The lead isotope 180Pb is found to still exhibit prolate excited structure, related to the known intruder structures in the heavier isotopes. The production cross-section of 180Pb was only 10 nb, one of the lowest ever employed in an in-beam experiment. A candidate for an excited prolate band was found in 192Po, making it the rst polonium isotope for which both oblate and prolate rotational bands have been established. Contrary to the previous results, the current experiments indicate that the onset of deformation in the radiu…
Yet another alien: a second species of Lepisiota spreading across the Canary Islands, Spain (Hymenoptera: Formicidae)
2018
The Canary Islands are a biologically important archipelago hosting many unique species, whose myrmecofauna is peculiarly rich in both endemic and introduced species. Lepisiota frauenfeldi cfr. kantarensis Forel, 1911 is reported for the first time from Fuerteventura and Tenerife. It is the second species of Lepisiota introduced in the archipelago in the last few years, and one of the few documented cases in which Lepisiota frauenfeldi (Mayr, 1855) s.l. acts as a successful tramp species. Comments are also given on taxonomic problems involving the L. frauenfeldi-group and related taxa. Finally, new additional information and comments are presented on the distribution of other alien ants spe…
The Higgs Era
2016
Después del descubrimiento de un bosón escalar con masa alrededor de 125, el Modelo Estándar parece funcionar perfectamente, pero todavía hay mucho espacio (y necesidad) para nueva física. A pesar de su enorme éxito, el Modelo Estándar deja muchas preguntas sin responder y muchas cuestiones abiertas. A falta del conocimiento de una simetría fundamental de la Naturaleza que nos indique el camino, hemos de analizar fenomenologicamente cualquier extensión del Modelo que pueda responder al menos a alguna de estas preguntas. En este trabajo estudiamos dos tipos de extensiones del Modelo Estándar, las dos relacionadas con el sector escalar. En la primera parte de la tesis estudiamos la posible ex…
Plant landscape and phytodiversity in the archeological area of Segesta (NW Sicily)
2018
In the system of Sicilian archaeological parks, the area of Segesta - an ancient city of western Sicily referring to the Carthaginian eparchy, - represents, together with Selinunte, Erice and Mothia, another integrated hotspot of biodiversity and archeaology. The current plant landscape is strongly influenced by a millenary anthropic transformation. There are no residual expressions of the original plant covering that, with reference to the environmental potential of the area, can be traced back to the evergreen Mediterranean forest dominated by Quercus ilex, presently only sporadically occurring in the area of the ruins, together with other species related to associations and upper syntaxa…
Studying Gamow-Teller transitions and the assignment of isomeric and ground states at $N=50$
2022
Direct mass measurements of neutron-deficient nuclides around the N=50 shell closure below $^{100}$Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of $^{124}$Xe, separated in the fragment separator FRS and delivered to the FRS-IC. The masses of 14 ground states and two isomers were measured with relative mass uncertainties down to 1×10−7 using the multiple-reflection time-of-flight mass spectrometer of the FRS-IC, including the first direct mass measurements of $^{98}$Cd and $^{97}$Rh. A new QEC=5437±67 keV was obtained for $^{98}$Cd, resulting in a summed Gamow-Teller (GT) strength for the five observed transitions (0+…
ALLERGENS IN THE PARK AND GARDEN FLORA OF SICILY
2017
The ornamental flora of parks and gardens, as we know, generally includes high proportions of exotics. In Italy it arose from Renaissance on and increasingly enriched up to include a large proportion of exotics native to countries under Mediterranean and temperate climates. Similarly the garden flora of Sicily has a large number of mostly Mediterranean and subtropical exotics. Even if very similar on the whole, these floras differ in some floristic, biological and ecological features. Indeed, several succulent families and genera that are rare or missing in Italy are frequent in Sicily, but plants from temperate regions are almost absent in the island. As regards the allergenic patterns ref…