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Intense and purified radioactive beam of post-accelerated $^{14}$O was used to study the low-lying states in the unbound $^{15}$F nucleus. Exploiting resonant elastic scattering in inverse kinematics with a thick target, the second excited state, a resonance at E$\_R$=4.757(6)(10)~MeV with a width of $\Gamma$=36(5)(14)~keV was measured for the first time with high precision. The structure of this narrow above-barrier state in a nucleus located two neutrons beyond the proton drip line was investigated using the Gamow Shell Model in the coupled channel representation with a $^{12}$C core and three valence protons. It is found that it is an almost pure wave function of two quasi-bound protons in the $2s\_{1/2}$ shell., Comment: 8 pages, 2 figures, 1 table, Submitted to Phys. Lett. B

We have measured the nuclear-matter distribution of the doubly-magic N = Z nucleus Ni-56 by investigating elastic proton scattering in inverse kinematics. The radioactive beam of Ni-56 was injected and stored in the experimental storage ring (ESR, GSI) and interacted with an internal hydrogen gas-jet target. The high revolution frequency of the ions in the ring enabled a high luminosity, despite the low density of the target being used. This way, measurements at very low momentum transfers became possible. By measuring the energy and the scattering angle of the recoiling protons, we were able to separate the elastic reaction channel from inelastic scattering to the first excited 2(+) state of Ni-56 and deduced the differential cross section of Ni-56 (p, p)(56) Ni. The data were analyzed within the framework of the Glauber multiple-scattering theory in order to extract the nuclear-matter radius and radial matter distribution of Ni-56. Parameterizing the matter distribution with the phenomenological Symmetrized Fermi distribution, a preliminary value of 3.5 fm for the rms matter radius was deduced. This experiment was part of an EXL (EXotic nuclei studied in Light-ion induced reactions at storage rings) campaign at GSI in 2012 and was the first successful investigation of nuclear reactions with a stored radioactive beam ever.

The determination of ratio of neutron over proton matrix elements by inelastic proton scattering, for 0(+)-->2(+) transitions, is investigated via the comparison between experimental data and theoretical calculations. Calculations into the context of a macroscopic and a microscopic description are performed for a wide mass range nuclei: O-18, Si-30, S-32,S-34, Ca-48, Sr-88, for which these ratios were determined previously with an independent technique. At that point the choice of the theoretical model may be very critical, It is thus the purpose of this investigation to point out the most suitable model. It is found that in general both theoretical models can be employed for the reliable determination of neutron over proton matrix element ratios. (C) 1999 Elsevier Science B.V. All rights reserved. Nuclear Physics A

Structure of weakly bound/unbound nuclei close to particle drip lines is different from that around the valley of beta stability. A comprehensive description of these systems goes beyond standard Shell Model and demands an open quantum system description of the nuclear many-body system. We approach this problem using the Gamow Shell Model which provides a fully microscopic description of bound and unbound nuclear states, nuclear decays, and reactions. We present in this paper the first application of the GSM for a description of the elastic and inelastic scattering of protons on 6He., Comment: Proc. Int. Conf. "Horizons of Innovative Theories, Experiments and Supercomputing in Nuclear Physics", June 4-7, 2012, New Orleans, Luisiana, USA; 10 pages, 4 figures

As a first step of the EXL project scheduled for the New Experimental Storage Ring at FAIR a precursor experiment (E105) was performed at the ESR at GSI. For this experiment, an innovative differential pumping concept, originally proposed for the EXL recoil detector ESPA, was successfully applied. The implementation and essential features of this novel technical concept will be discussed, as well as details on the detectors and the infrastructure around the internal gas-jet target. With Ni-56(p, p)Ni-56 elastic scattering at 400 MeV u(-1), a nuclear reaction experiment with stored radioactive beams was realized for the first time. Finally, perspectives for a next-generation EXL-type setup are briefly discussed.

The reaction cross section for the halo nucleus He-6 on hydrogen has been measured at 36 MeV/nucleon using the transmission method and a value of sigma (R) = 409 +/- 22 mb was: obtained. A coherent analysis within a microscopic model of this result in conjunction with (p, p) and (p, n) angular distributions has allowed the interaction potential to be uniquely determined. This analysis also allowed the He-6 density distribution to be explored. (C) 2001 Elsevier Science B.V. All rights reserved. Physics Letters B

The model of microscopic optical potential based on calculations of the one-particle Green function mass operator using the effective Skyrme nucleon-nucleon forces has been applied for describing cross sections and analyzing powers of the elastic nucleon-nucleus scattering. The Skyrme force parameters have been optimized by fitting a chosen angular distribution of the elastic neutron-nucleus scattering with simultaneous control of main characteristics of the nuclear matter and the binding energy and rms charge radius of the target nucleus. The found Skyrme forces have been used to analyze differential cross sections and analyzing powers of elastic neutron scattering by nuclei in a wide range of mass numbers. The calculations have given a satisfactory description of experimental data on elastic neutron-nucleus scattering and reasonable values of the main parameters for the symmetric nuclear matter and even-even nuclei. Analogous calculations have been performed for describing experimental data on the elastic proton-nucleus scattering, which have yielded encouraging results.