321 research outputs found
Model nuclear energy density functionals derived from \emph{ab initio} calculations
No full textWe present the rst application of a new approach, proposed in [Journal of Physics G: Nuclear and Particle Physics, vol. 43, 04LT01 (2016)] to derive coupling constants of the Skyrme energy density functional (EDF) from ab initio Hamiltonian. By perturbing the ab initio Hamiltonian with several functional generators dening the Skyrme EDF, we create a set of metadata that is then used to constrain the coupling constants of the functional. We use statistical analysis to obtain such an ab initioequivalent Skyrme EDF. We nd that the resulting functional describes properties of atomic nuclei and innite nuclear matter quite poorly. This may point out to the necessity of building up the ab initio-equivalent functionals from more sophisticated generators. However, we also indicate that the current precision of the ab initio calculations may be insucient for deriving meaningful nuclear EDFs
The class of “reactives” against the so-called “paratactemes”
No full textPorównanie dwóch tytułowych nie do końca kompatybilnych klas, tj. dopowiedzeń (w rozumieniu R. Laskowskiego) i tzw. parataktemów (w rozumieniu J. Wajszczuk) stanowi punkt wyjścia dla próby uporządkowania zróżnicowania wewnętrznego tych drugich, w których Wajszczuk widziała przede wszystkim dwupozycyjne spójniki i jednopozycyjne partykuły. Specyfika dopowiedzeń polegająca na prymarnej samodzielności wypowiedzeniowej nie tylko pozwala na odróżnienie ich od pozostałych parataktemów, w szczególności partykuł, które wpisują się płynnie w linię prozodyczną wypowiedzenia, lecz także zwraca uwagę na dogodność kryterium prozodycznego w porządkowaniu zróżnicowanej wewnętrzne klasy parataktemów. W artykule zaproponowane zostały wstępne kryteria takiego uporządkowania.The starting point of the paper is a comparison of two classes of lexemes that are not entirely compatible, i.e., “reactives” (pol. “dopowiedzenia”, as defined by R. Laskowski) and “paratactemes” (as defined by J. Wajszczuk). The author attempts to sort out the internal diversity of the latter, which Wajszczuk saw primarily as encompassing two-position conjunctions and single-position particles. The specificity of “reactives”, consisting in their primary prosodic and syntactic independence, allows not only to distinguish them from other paratactemes, in particular particles that fit smoothly into the prosodic line of the utterance, but also draws attention to the handiness of the prosodic criterion in organising the internally diverse class of paratactemes. The article proposes preliminary criteria for such an ordering
Mass number dependence of nuclear pairing
No full textAbstractLarge scale Hartree–Fock–Bogoliubov (HFB) calculations with the finite-range Gogny force D1S have been performed in order to extract the corresponding theoretical average mass dependence of the nuclear gap values. Good agreement with experimental data from the three-point filter Δ(3)(N) with N odd has been found for both the neutron and proton gaps. The results of our study support earlier findings [W. Satuła, J. Dobaczewski, W. Nazarewicz, Phys. Rev. Lett. 81 (1998) 3599] that the mass dependence of the gap is much weaker than the so far accepted 12A−1/2 MeV law
Klasa dopowiedzeń na tle tzw. parataktemów
No full textPorównanie dwóch tytułowych nie do końca kompatybilnych klas, tj. dopowiedzeń (w rozumieniu R. Laskowskiego) i tzw. parataktemów (w rozumieniu J. Wajszczuk) stanowi punkt wyjścia dla próby uporządkowania zróżnicowania wewnętrznego tych drugich, w których Wajszczuk widziała przede wszystkim dwupozycyjne spójniki i jednopozycyjne partykuły. Specyfika dopowiedzeń polegająca na prymarnej samodzielności wypowiedzeniowej nie tylko pozwala na odróżnienie ich od pozostałych parataktemów, w szczególności partykuł, które wpisują się płynnie w linię prozodyczną wypowiedzenia, lecz także zwraca uwagę na dogodność kryterium prozodycznego w porządkowaniu zróżnicowanej wewnętrzne klasy parataktemów. W artykule zaproponowane zostały wstępne kryteria takiego uporządkowania
Skyrme effective pseudopotential up to the next-to-next-to-leading order
No full textThe explicit form of the next-to-next-to-leading order ((NLO)-L-2) of the Skyrme effective pseudopotential compatible with all required symmetries and especially with gauge invariance is presented in a Cartesian basis. It is shown in particular that for such a pseudopotential there is no spin-orbit contribution and that the D-wave term suggested in the original Skyrme formulation does not satisfy the invariance properties. The six new (NLO)-L-2 terms contribute to both the equation of state and the Landau parameters. These contributions to symmetric nuclear matter are given explicitly and discussed.This work was supported by the NESQ project (ANR-BLANC 0407, France) and Mineco (Spain), grant FIS2011-28617-C02-02. The authors thank M Bender, K Bennaceur, B G Carlsson, J Dobaczewski, T Duguet, J Meyer and F Raimondi for stimulating and encouraging discussions and for useful comments.Peer reviewe
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Contact Pairing Interaction for the Hartree-Fock-Bogoliubov Calculations
No full textProperties of density-dependent contact pairing interactions in nuclei are discussed. It is shown that the pairing interaction that is intermediate between surface and volume pairing forces gives the pairing gaps that are compatible with the experimental odd-even mass staggering. Results of the deformed Hartree-Fock-Bogoliubov calculations for this ''mixed'' pairing interaction, and using the transformed harmonic oscillator basis, are presented
A new avenue in the search for CP violation: Mössbauer spectroscopy of 227Ac
No full textThis work proposes a new avenue in the search for CP-violating odd-electric and even-magnetic nuclear moments. A promising candidate to find such moments in the ground state is the quadrupole-deformed and octupole-correlated nucleus 227-actinium. In this nucleus, the 27.4-keV E1 transition that connects the 3/2+ parity-doublet partner and the 3/2− ground state is perfectly suited to apply the sensitive technique of recoil-free selfabsorption, commonly known as Mössbauer spectroscopy. In this experimental approach, the lifetime of the 3/2+ upper parity-doublet partner allows an estimate of the lower limit of ΔE = 2 · Γγ = 23.7(1) × 10−9 eV for the achievable energy resolution to be made. This resolution must be exceeded by the interaction of a CP-violating moment and the corresponding multipole moment of the field distribution in the lattice. This work presents the first ideas for patterns caused by CP-violating moments on the expected quadrupole splitting and nuclear Zeeman effect.Output Status: Forthcomin
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