Results 1 - 10 of 14150
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[en] Pairing reduction in deformed nuclei due to the blocking effect is treated exactly with the particle-number-conserving method. Merely due to the blocking effect the gap parameter Δ becomes configuration-dependent. The pairing reduction delta(ν0) depends sensitively on the location of the blocked level ν0 relative to the Fermi surface, lambda, and decreases rapidly with vertical strokeepsilonν0lambdavertical stroke. The pairing reduction delta(ν0) depends also sensitively on the single-particle level distribution near the Fermi surface. In some special cases pairing reduction may be negative. With an increasing number of the blocked levels (above the Fermi surface) the gap parameter Δ decreases dramatically. If the blocked levels are below the Fermi surface the situation is quite different and as the number of the blocked levels becomes sufficiently large the pairing reduction may vanish. (orig.)
[en] Symmetry and pairing energies of atomic nuclei are related to the differences between the excitation energies of isobaric analog states in the same nucleus. Numerous such excitation energies are known experimentally. In addition, a comprehensive global set can be deduced from the available experimental masses by applying Coulomb energy corrections. Replacing the experimental mass data by available theoretical mass predictions as basis for this procedure to extract symmetry and pairing energies makes it possible to directly compare theoretical and experimental quantities. These comparisons reflect upon the goodness or possible shortcomings of the respective mass equation since symmetry energies are related to the curvature of the nuclear mass surface. A discussion of eleven selected mass equations or procedures for reproducing experimental masses and extrapolating into regions of unknown nuclei is presented
[en] Penetrability through a three-humped barrier has been calculated in quasi-classical approximation and a plausible explanation of sub-barrier fission characteristics of thorium is suggested. (Auth.)
[en] In this work, we have systemically investigated the ground-state properties of the rare-earth even-even nuclei with the parameter set FSUGold that includes the isoscalar-isovector coupling to soften the symmetry energy. It is the first time that this parameter set is applied to investigate the properties of deformed nuclei. The present study is mainly focused on the nuclei with the known experimental binding energies ranging from Z=58 to Z=70. The calculated binding energies, quadrupole deformations, and charge radii are in good agreement with the available experimental data. It has been shown that the parameter set FSUGold is as successful as the NL3 in reproducing the known ground-state properties of deformed nuclei.
[en] A fully consistent relativistic random phase approximation (RRPA) built on the relativistic mean field (RMF) ground state is applied to study the giant multipole resonances of stable nuclei. The fully consistent RRPA requires that the nuclear RMF wave function and the RRPA renormalization are calculated in a same effective Lagrangian. A theoretically complete treatment of the RRPA at the mean-field level must include not only the usual particle-hole states, but also the pairs formed from the occupied Fermi states and Dirac states. Effects of inclusion of Dirac sea states in various multipole excitations are investigated. Applications to exotic nuclei, such as Ca-isotopes are presented
[en] We have studied the fission parameters of hot neutron-rich thermally fissile and nuclei within the temperature dependent effective field theory motivated relativistic mean field (E-TRMF) formalism by using the recently developed FSUGarnet and IOPB-I parameter sets. The results obtained by these two forces are compared with the results of the well known and widely accepted NL3 parameter set. The excitation energy , shell correction energy , single particle energy for neutrons and protons , level density parameter a, neutron skin thickness ΔR, two neutron separation energy , and asymmetry energy coefficient of these neutron-rich thermally fissile nuclei are calculated at finite temperature. The dependency of level density parameter and other observables on the temperature and the force parameters (interaction Lagrangian) are discussed.
[en] A finite well potential of cylindrical shape is used to study the changes in the particle density distribution with rotation. Changes in the Coulomb energy and in the second moment < r2> are calculated for five nuclei with A between 40 and 220 and the deformation ratio 1:1 to 3:2. The critical angular momentum for particle emission is found to be M less than approximately A and the Coulomb energy to decrease by up to 3%. (Auth.)
[en] Conditions which must be fulfilled by clusters of nucleons to qualify as elementary modes of excitation are analysed in terms of single criteria involving experimental binding energies. It is found that the most complex possible mode is the α-like cluster. (orig.)