Study of reactions induced by 6He on 9Be

INPC 2013 – International Nuclear Physics ConferenceWe present the results of experiments using a 6He beam on a 9Be target at energies 7 − 9 times the Coulomb barrier. Angular distributions of the elastic, inelastic scattering (target breakup) and the a-particle production in the 6He+9Be collision have been analysed. Total reaction cross sections were obtained from the elastic scatteringanalyses and a considerable enhancement has been observed by comparing to stable system

Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

Abstract. The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay halflife. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported and the experimental challenges characterizing such activity are describe

NURE: An ERC project to study nuclear reactions for neutrinoless double beta decay

Neutrinoless double beta decay (0νββ) 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 0νββ 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 extract information on the 0νββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0νββ

Study of high lying resonances in 9Be by the Measurement of (p, p), (p,α) and (p, d) reactions

The (p, p), (p, α) and (p, d) reactions on 8Li were measured at low energies. The experiment was performed using a thick [CH2]n target and a radioactive 8Li beam available at the RIBRAS facility of São Paulo. This experiment represents an upgrade of a previous experiment, where only the 8Li(p, a)5He cross section was measured. High lying resonances of 9Be, which are still uncertain, could be studied in this way. The detection of several reaction channels allows a reliable determination of the resonance parameters, such as energy, width and spin-parity. In the deuteron channel we could observe the same resonance decaying to d+7Ligs and to d+7Li&z.ast; The properties of the resonances are determined by a R-matrix analysis, which provides evidence for a significant clustering as well in the (p, α) as in the (p, d) channels. The experimental data and the multi-channel R-matrix analysis will be presented.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

Nutritional value of some feedstuffs used in the diet of captive capybaras

Five pen-raised adult female capybaras were used in five digestibility trials in a Latin square design, to determine, for capybaras, the nutritional values of Cameroon grass (Pennisetum purpureum cv. Cameroon); Napier grass (P. purpureum cv. Napier); corn grain; cassava hay, comprising leaves and stems; and palm kernel (Elaeis guineensis) cake. These feedstuffs were provided separately or mixed, in a completely randomized manner, in different experimental periods. The digestibility of each feedstuff not supplied alone was estimated by difference. The animals were individually introduced in metabolism pens. Following a 10-day period of adaptation to each diet, feed intake was recorded and total fecal output was collected over five consecutive days. Energy, crude protein and neutral detergent fiber digestibilities of Cameroon grass were, respectively, 0.88 (±0.07, standard deviation), 0.63 (±0.39) and 0.82 (±0.15). For Napier grass they were 0.84 (±0.05), 0.63 (±0.12) and 0.72 (±0.10); for corn grain, 0.92 (±0.05), 0.97 (±0.20) and 0.83 (±0.14); for cassava hay, 0.86 (±0.12), 0.84 (±0.14) and 0.43 (±0.16); and for palm kernel cake 0.94 (±0.05), 0.85 (±0.14), and 0.97 (±0.05). These digestibilities in capybaras were higher than the digestibilities of the same feedstuffs in other livestock. These results can be explained by the anatomical and physiological characteristics of the capybara, which lead to a high rate of nutrient digestion and absorption

The 8Li(p,α)5He reaction at low energies, and 9Be spectroscopy around the proton threshold

We present a direct measurement of the low-energy 8Li(p ,α)5He cross section, using a radioactive 8Li beam impinging on a thick target. With four beam energies, we cover the energy range between Ec.m.=0.2 and 2.1 MeV. An R-matrix analysis of the data is performed and suggests the existence of two broad overlapping resonances (5/2+ at Ec.m.=1.69 MeV and 7/2+ at E c.m.=1.76 MeV). At low energies our data are sensitive to the properties of a subthreshold state (Ex=16.67 MeV) and of two resonances above threshold. These resonances were observed in previous experiments. The R-matrix fit confirms spin assignments, and provides partial widths. We propose a new 8Li(p,α)5He reaction rate and briefly discuss its influence in nuclear astrophysics. © 2012 American Physical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe