33,313 research outputs found

    Binding-energy independence of reduced spectroscopic strengths derived from (p, 2p) and (p, pn) reactions with nitrogen and oxygen isotopes

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    A campaign of intermediate energy (300-450 MeV/u) proton-induced nucleon knockout measurements in inverse kinematics has been recently undertaken at the R 3 B/LAND setup at GSI. We present a systematic theoretical analysis of these data with the aim of studying the quenching of the single-particle strengths and its binding-energy dependence. For that, the measured semi-inclusive (p, 2p) and (p, pn) cross sections are compared with theoretical predictions based on single-particle cross sections derived from a novel coupled-channels formalism and shell-model spectroscopic factors. A systematic reduction of about 20-30% is found, with a very limited dependence on proton-neutron asymmetry.Comment: 8 pages, 3 figure

    Description of the 11^{11}Li(p,d)10(p,d){^{10}}Li transfer reaction using structure overlaps from a full three-body model

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    Recent data on the differential angular distribution for the transfer reaction 11^{11}Li(p,d)10^{10}Li at E/A=5.7E/A=5.7 MeV in inverse kinematics are analysed within the DWBA reaction framework, using the overlap functions calculated within a three-body model of 11^{11}Li. The weight of the different 10^{10}Li configurations in the system's ground state is obtained from the structure calculations unambiguously. The effect of the 9^{9}Li spin in the calculated observables is also investigated. We find that, although all the considered models succeed in reproducing the shape of the data, the magnitude is very sensitive to the content of p1/2p_{1/2} wave in the 11^{11}Li ground-state wave function. Among the considered models, the best agreement with the data is obtained when the 11^{11}Li ground state contains a \sim31\% of p1/2p_{1/2} wave in the nn-9^9Li subsystem. Although this model takes into account explicitly the splitting of the 1+1^+ and 2+2^+ resonances due to the coupling of the p1/2p_{1/2} wave to the 3/23/2^- spin of the core, a similar degree of agreement can be achieved with a model in which the 9^{9}Li spin is ignored, provided that it contains a similar p-wave content.Comment: 8 pages, 3 figures. Final versio

    Linking structure and dynamics in (p,pn)(p,pn) reactions with Borromean nuclei: the 11^{11}Li(p,pn)10(p,pn){^{10}}Li case

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    One-neutron removal (p,pn)(p,pn) reactions induced by two-neutron Borromean nuclei are studied within a Transfer-to-the-Continuum (TC) reaction framework, which incorporates the three-body character of the incident nucleus. The relative energy distribution of the residual unbound two-body subsystem, which is assumed to retain information on the structure of the original three-body projectile, is computed by evaluating the transition amplitude for different neutron-core final states in the continuum. These transition amplitudes depend on the overlaps between the original three-body ground-state wave function and the two-body continuum states populated in the reaction, thus ensuring a consistent description of the incident and final nuclei. By comparing different 11^{11}Li three-body models, it is found that the 11^{11}Li(p,pn)10(p,pn){^{10}}Li relative energy spectrum is very sensitive to the position of the p1/2p_{1/2} and s1/2s_{1/2} states in 10^{10}Li and to the partial wave content of these configurations within the 11^{11}Li ground-state wave function. The possible presence of a low-lying d5/2d_{5/2} resonance is discussed. The coupling of the single particle configurations with the non-zero spin of the 9^{9}Li core, which produces a spin-spin splitting of the states, is also studied. Among the considered models, the best agreement with the available data is obtained with a 11^{11}Li model that incorporates the actual spin of the core and contains \sim31\% of p1/2p_{1/2}-wave content in the nn-9^9Li subsystem, in accord with our previous findings for the 11^{11}Li(p,d)10^{10}Li transfer reaction, and a near-threshold virtual state.Comment: 7 pages, 4 figures, submitted to PL

    Investigating the 10Li continuum through 9Li(d,p)10Li reactions

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    The continuum structure of the unbound system 10^{10}Li, inferred from the 9^{9}Li(d,p)10(d,p)^{10}Li transfer reaction, is reexamined. Experimental data for this reaction, measured at two different energies, are analyzed with the same reaction framework and structure models. It is shown that the seemingly different features observed in the measured excitation energy spectra can be understood as due to the different incident energy and angular range covered by the two experiments. The present results support the persistence of the N=7N=7 parity inversion beyond the neutron dripline as well as the splitting of the well-known low-lying pp-wave resonance. Furthermore, they provide indirect evidence that most of the =2\ell=2 single-particle strength, including possible d5/2d_{5/2} resonances, lies at relatively high excitations energies.Comment: accepted for publication in Physics Letters

    LabelTranslator: A Tool to Automatically Localize an Ontology

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    This demo proposal briefly presents LabelTranslator, a system that suggests translations of ontology labels, with the purpose of localizing ontologies. LabelTranslator takes as input an ontology whose labels are described in a source natural language and obtains the most probable translation of each ontology label into a target natural language.Our main contribution is the automatization of this process, which reduces human efforts to localize manually the ontology

    Determining B(E1)B(E1) distributions of weakly bound nuclei from breakup cross sections using Continuum Discretized Coupled Channels calculations. Application to 11^{11}Be

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    A novel method to extract the B(E1)B(E1) strength of a weakly bound nucleus from experimental Coulomb dissociation data is proposed. The method makes use of continuum discretized coupled channels (CDCC) calculations, in which both nuclear and Coulomb forces are taken into account to all orders. This is a crucial advantage with respect to the standard procedure based on the Equivalent Photon Method (EPM) which does not properly take into account nuclear distortion, higher order coupling effects, or Coulomb-nuclear interference terms. The procedure is applied to the 11^{11}Be nucleus using two sets of available experimental data at different energies, for which seemingly incompatible B(E1)B(E1) have been reported using the EPM. We show that the present procedure gives consistent B(E1)B(E1) strengths, thus solving the aforementioned long-standing discrepancy between the two measurements.Comment: Submitted for publicatio

    ODESWS, A Semantic Web Service Development

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    ODE SWS is a development environment to design Semantic Web Services (SWS) at the knowledge level. ODE SWS describe the service following a problem-solving approach in which the SWS are modeled using tasks, to represent the SWS functional features, and methods, to describe the SWS internal structure. In this paper, we describe the ODE SWS architecture and the capabilities of its graphical interface, which enables users to design SWS independently of the semantic markup language used to represent them

    Estimation of unsteady aerodynamic forces using pointwise velocity data

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    A novel method to estimate unsteady aerodynamic force coefficients from pointwise velocity measurements is presented. The methodology is based on a resolvent-based reduced-order model which requires the mean flow to obtain physical flow structures and pointwise measurement to calibrate their amplitudes. A computationally-affordable time-stepping methodology to obtain resolvent modes in non-trivial flow domains is introduced and compared to previous existing matrix-free and matrix-forming strategies. The technique is applied to the unsteady flow around an inclined square cylinder at low Reynolds number. The potential of the methodology is demonstrated through good agreement between the fluctuating pressure distribution on the cylinder and the temporal evolution of the unsteady lift and drag coefficients predicted by the model and those computed by direct numerical simulation.Comment: In revie

    SWSDesigner: The Graphical Interface of ODESWS

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    ODESWS is a development environment to design Semantic Web Services (SWS) at the knowledge level. ODESWS describe the service following a problem-solving approach in which the SWS are modelled using tasks, to represent the SWS functional features, and methods, to describe the SWS internal structure. In this paper, we describe the ODESWS graphical interface (called SWSDesinger). This interface enables users to design SWS independently of the semantic markup language in which the service will be implemented, and once the design has been export the service to an SWS implementation languag
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