7,542 research outputs found

    Medium effects of magnetic moments of baryons on neutron stars under strong magnetic fields

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    We investigate medium effects due to density-dependent magnetic moments of baryons on neutron stars under strong magnetic fields. If we allow the variation of anomalous magnetic moments (AMMs) of baryons in dense matter under strong magnetic fields, AMMs of nucleons are enhanced to be larger than those of hyperons. The enhancement naturally affects the chemical potentials of baryons to be large and leads to the increase of a proton fraction. Consequently, it causes the suppression of hyperons, resulting in the stiffness of the equation of state. Under the presumed strong magnetic fields, we evaluate relevant particles' population, the equation of state and the maximum masses of neutron stars by including density-dependent AMMs and compare them with those obtained from AMMs in free space

    Coupled-channels analyses for 9,11^{9,11}Li + 208^{208}Pb fusion reactions with multi-neutron transfer couplings

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    We discuss the role of two-neutron transfer processes in the fusion reaction of the 9,11^{9,11}Li + 208^{208}Pb systems. We first analyze the 9^{9}Li + 208^{208}Pb reaction by taking into account the coupling to the 7^{7}Li + 210^{210}Pb channel. To this end, we assume that two neutrons are directly transferred to a single effective channel in 210^{210}Pb and solve the coupled-channels equations with the two channels. By adjusting the coupling strength and the effective QQ-value, we successfully reproduce the experimental fusion cross sections for this system. We then analyze the 11^{11}Li + 208^{208}Pb reaction in a similar manner, that is, by taking into account three effective channels with 11^{11}Li + 208^{208}Pb, 9^{9}Li + 210^{210}Pb, and 7^{7}Li + 212^{212}Pb partitions. In order to take into account the halo structure of the 11^{11}Li nucleus, we construct the potential between 11^{11}Li and 208^{208}Pb with a double folding procedure, while we employ a Wood-Saxon type potential with the global Aky\"uz-Winther parameters for the other channels. Our calculation indicates that the multiple two-neutron transfer process plays a crucial role in the 11^{11}Li + 208^{208}Pb fusion reaction at energies around the Coulomb barrier

    Fusion reaction of a weakly-bound nucleus with a deformed target

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    We discuss the role of deformation of the target nucleus in the fusion reaction of the 15^{15}C + 232^{232}Th system at energies around the Coulomb barrier, for which 15^{15}C is a well-known one-neutron halo nucleus. To this end, we construct the potential between 15^{15}C and 232^{232}Th with the double folding procedure, assuming that the projectile nucleus is composed of the core nucleus, 14^{14}C, and a valance neutron. By taking into account the halo nature of the projectile nucleus as well as the deformation of the target nucleus, we simultaneously reproduce the fusion cross sections for the 14^{14}C + 232^{232}Th and the 15^{15}C + 232^{232}Th systems. Our calculation indicates that the net effect of the breakup and the transfer channels is small for this system.Comment: 7 pages, 5 figure

    Two Circular-Rotational Eigenmodes in Vortex Gyrotropic Motions in Soft Magnetic Nanodots

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    We found, by micromagnetic numerical and analytical calculations, that the clockwise (CW) and counterclockwise (CCW) circular-rotational motions of a magnetic vortex core in a soft magnetic circular nanodot are the elementary eigenmodes existing in the gyrotropic motion with respect to the corresponding CW and CCW circular-rotational-field eigenbasis. Any steady-state vortex gyrotropic motions driven by a linearly polarized oscillating in-plane magnetic field in the linear regime can be perfectly understood according to the superposition of the two circular eigenmodes, which show asymmetric resonance characteristics reflecting the vortex polarization. The relative magnitudes in the amplitude and phase between the CCW and CW eigenmodes determine the elongation and orientation of the orbital trajectories of the vortex core motions, respectively, which trajectories vary with the polarization and chirality of the given vortex as well as the field frequency across the resonance frequency.Comment: 30 pages, 7 figure

    Extended optical model analyses of 11^{11}Be+197^{197}Au with dynamic polarization potentials

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    We discuss angular distributions of elastic, inelastic, and breakup cross sections for 11^{11}Be + 197^{197}Au system, which were measured at energies below and around Coulomb barrier. To this end, we employ Coulomb dipole excitation (CDE) and long-range nuclear (LRN) potential to take into account long range effects by halo nuclear system and break up effects by weakly-bound structure. We then analyze recent experimental data including 3-channes i.e. elastic, inelastic, and breakup cross sections, at Ec.m.E_{\textrm{c.m.}}=29.6 MeV and Ec.m.E_{\text{c.m.}}=37.1 MeV. From the extracted parameter sets using χ2\chi^{2} analysis, we successfully reproduce the experimental angular distributions of the elastic, inelastic, and breakup cross sections for 11^{11}Be+197^{197}Au system simultaneously. Also we discuss the necessity of LRN potential around Coulomb barrier from analyzed experimental data

    Suppression of the elastic scattering cross section for 17Ne + 208Pb system

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    We investigated the elastic scattering, inelastic scattering, breakup reaction, and total fusion reactions of 17Ne + 208Pb system using the optical model (OM) and a coupled channel (CC) approaches. The aim of this study is to elucidate the suppress of the elastic cross-section that is invisible in proton-rich nuclei such as 8B and 17F projectiles but appears in neutron-rich nuclei such as 11Li and 11Be projectiles. The results revealed that this suppression was caused mainly by the nuclear interaction between the projectile and target nucleus rather than the strong Coulomb interaction observed in neutron-rich nuclei and the contributions of Coulomb excitation interaction due to two low-lying E2 resonance states are relatively small. From the simultaneous chi-square analysis of the 17Ne + 208Pb system, we can infer a strong suppression effect in the elastic scattering cross-section due to the nuclear interaction between the projectile and target nucleus, rather than the Coulomb interaction as observed in neutron-rich nuclei. Also, the contribution of the direct reaction, comprising the inelastic scattering and breakup reaction cross-sections, accounted for almost half of the total reaction. Finally, we perform the CC calculation using the parameters obtained from our OM calculation but our CC calculations could not explain the 15O production cross section.Comment: 20 pages, 7 figure

    The role of sexual orientation, age, living arrangements and self-rated health in planning for end-of-life care for lesbian, gay and bisexual (LGB) older people in the UK

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    © The Author(s) 2020. The final, definitive version of this paper has been published in Sexualities by Sage Publications Ltd. All rights reserved. It is available at: https://doi.org/10.1177/1363460720932381.This article reports on findings from the quantitative phase of a two-year research project designed to explore end-of-life care experiences and needs of lesbian, gay, bisexual and transgender people. We draw on a subset of the sample (N = 180/237) to analyse the relationship between advance care planning, sexual orientation, living arrangements and self-rated health. The results contribute to a growing body of evidence on how sexual minorities approach and make decisions on advance care planning. A greater understanding of such patterns could help inform the way healthcare professionals engage in conversations about end-of-life care planning with older LGB people.Peer reviewe

    Ultrafast vortex-core reversal dynamics in ferromagnetic nanodots

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    To verify the exact underlying mechanism of ultrafast vortex-core reversal as well as the vortex state stability, we conducted numerical calculations of the dynamic evolution of magnetic vortices in Permalloy cylindrical nanodots under an oscillating in-plane magnetic field over a wide range of the field frequency and amplitude. The calculated results reveal different kinds of the nontrivial dynamic responses of vortices to the driving external field, including the vortex-core reversal. In particular, the results offer insight into the 10 ps scale underlying physics of the ultrafast vortex-core reversal driven by small-amplitude (similar to 10 Oe) oscillating in-plane fields. This work also provides fundamentals of how to effectively manipulate the vortex dynamics as well as the dynamical switching of the vortex-core orientation.open624

    Zero Temperature Chiral Phase Transition in (2+1)-Dimensional QED with a Chern-Simons Term

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    We investigate the zero temperature chiral phase transition in (2+1)-dimensional QED in the presence of a Chern-Simons term, changing the number of fermion flavors. In the symmetric phase, there are no light degrees of freedom even at the critical point. Unlike the case without a Chern-Simons term, the phase transition is first-order.Comment: 7 pages, RevTeX, no figure
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