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Song, J., Dai, L. R., & Oset, E. (2022). How much is the compositeness of a bound state constrained by a and r(0)? The role of the interaction range. Eur. Phys. J. A, 58(7), 133–10pp.
Abstract: We present an approach that allows one to obtain information on the compositeness of molecular states from combined information of the scattering length of the hadronic components, the effective range, and the binding energy. We consider explicitly the range of the interaction in the formalism and show it to be extremely important to improve on the formula of Weinberg obtained in the limit of very small binding and zero range interaction. The method allows obtaining good information also in cases where the binding is not small. We explicitly apply it to the case of the deuteron and the D-s0* (2317) and D-s1* (2460) states and determine simultaneously the value of the compositeness within a certain range, as well as get qualitative information on the range of the interaction.
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n_TOF Collaboration(Mastromarco, M. et al), Domingo-Pardo, C., & Tain, J. L. (2022). High accuracy, high resolution U-235(n,f) cross section from n_TOF (CERN) from 18 meV to 10 keV. Eur. Phys. J. A, 58(8), 147–13pp.
Abstract: The U-235(n,f) cross section was measured in a wide energy range (18 meV-170 keV) at the nTOF facility at CERN, relative to Li-6(n,t) and B-10(n,alpha) standard reactions, with high resolution and accuracy, with a setup based on a stack of six samples and six silicon detectors placed in the neutron beam. In this paper we report on the results in the region between 18 meV and 10 keV neutron energy. A resonance analysis has been performed up to 200 eV, with the code SAMMY. The resulting fission kernels are compared with the ones extracted on the basis of the resonance parameters of the most recent major evaluated data libraries. A comparison of the nTOF data with the evaluated cross sections is also performed from thermal to 10 keV neutron energy for the energy-averaged cross section in energy groups of suitably chosen width. A good agreement, within 0.5%, is found on average between the new results and the latest evaluated data files ENDF/B-VIII.0 and JEFF-3.3, as well as with respect to the broad group average fission cross section established in the framework of the standard working group of IAEA (the so-called reference file). However, some discrepancies, of up to 4%, are still present in some specific energy regions. The new dataset here presented, characterized by a unique combination of high resolution and accuracy, low background and wide energy range, can help to improve the evaluations from the Resolved Resonance Region up to 10 keV, also reducing the uncertainties that affect this region.
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R3B Collaboration(Heil, M. et al), & Nacher, E. (2022). A new Time-of-flight detector for the (RB)-B-3 setup. Eur. Phys. J. A, 58(12), 248–19pp.
Abstract: We present the design, prototype developments and test results of the new time-of-flight detector (ToFD) which is part of the R3B experimental setup at GSI and FAIR, Darmstadt, Germany. The ToFD detector is able to detect heavy-ion residues of all charges at relativistic energies with a relative energy precision sigma_Delta E/Delta E of up to 1% and a time precision of up to 14 ps (sigma). Together with an elaborate particle-tracking system, the full identification of relativistic ions from hydrogen up to uranium in mass and nuclear charge is possible.
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n_TOF Collaboration(Lederer-Woods, C. et al), Domingo-Pardo, C., Tain, J. L., & Tarifeño-Saldivia, A. (2022). Ge-74(n, gamma) cross section below 70 keV measured at n_TOF CERN. Eur. Phys. J. A, 58(12), 239–9pp.
Abstract: Neutron capture reaction cross sections on Ge-74 are of importance to determine Ge-74 production during the astrophysical slow neutron capture process. We present new resonance data on Ge-74(n, gamma ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.
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n_TOF Collaboration(Domingo-Pardo, C. et al), Babiano-Suarez, V., Balibrea-Correa, J., Caballero, L., Ladarescu, I., Lerendegui-Marco, J., et al. (2023). Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF. Eur. Phys. J. A, 59(1), 8–11pp.
Abstract: This article presents a few selected developments and future ideas related to the measurement of (n, gamma ) data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with gamma- ray imaging capability for background suppression, and the development of an array of small-volume organic scintilla tors aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate i neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area.
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