4,190 research outputs found

    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

    A new formulation of compartmental epidemic modelling for arbitrary distributions of incubation and removal times

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    The paradigm for compartment models in epidemiology assumes exponentially distributed incubation and removal times, which is not realistic in actual populations. Commonly used variations with multiple exponentially distributed variables are more flexible, yet do not allow for arbitrary distributions. We present a new formulation, focussing on the SEIR concept that allows to include general distributions of incubation and removal times. We compare the solution to two types of agent-based model simulations, a spatially homogeneous one where infection occurs by proximity, and a model on a scale-free network with varying clustering properties, where the infection between any two agents occurs via their link if it exists. We find good agreement in both cases. Furthermore a family of asymptotic solutions of the equations is found in terms of a logistic curve, which after a non-universal time shift, fits extremely well all the microdynamical simulations. The formulation allows for a simple numerical approach; software in Julia and Python is provided.Comment: 21 pages, 11 figures. v2 matches published version: improved presentation (including title, abstract and references), results and conclusions unchange

    Historiografía de los queros, pajchas y otras vasijas lígneas andinas de época incaica y colonial del Museo de América (Madrid)

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    Este articulo analiza les diferentes estudios que han tratado de los `queros', `pajehas' y otros recipientes de madera del Area Central Andina de la época Inca y colonial que se encuentran en el Museo de América de Madrid.This artiele analyse different werks abeul `queros', `pajchas' and elber types of wood receptacles of the Central Andean Aren. These receptacles date frem the Inca and Colonial periods, and are located al Ihe Museo de América, in Madrid
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