The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
J.m. Pearson - One of the best experts on this subject based on the ideXlab platform.
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Hartree-Fock-Bogoliubov Nuclear Mass model with 0.50 MeV accuracy based on standard forms of Skyrme and pairing functionals
Physical Review C, 2013Co-Authors: Stéphane Goriely, Nicolas Chamel, J.m. PearsonAbstract:We present a new Hartree-Fock-Bogoliubov Nuclear Mass model based on standard forms of Skyrme and pairing functionals, which corresponds to the most accurate Mass model we ever achieved within the framework of the Nuclear energy density functional theory. Our new Mass model is characterized by a model standard deviation σmod = 0.500 MeV with respect to essentially all the 2353 available Mass data for nuclei with neutron and proton numbers larger than 8. At the same time, the underlying Skyrme functional yields a realistic description of infinite homogeneous Nuclear matter properties, as determined by realistic calculations and by experiments; these include in particular the incompressibility coefficient, the pressure in charge-symmetric Nuclear matter, the neutron-proton effective Mass splitting, the stability against spin and spin-isospin fluctuations, as well as the neutron-matter equation of state.
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skyrme hartree fock bogoliubov Nuclear Mass formulas crossing the 0 6 mev accuracy threshold with microscopically deduced pairing
Physical Review Letters, 2009Co-Authors: Stéphane Goriely, Nicolas Chamel, J.m. PearsonAbstract:We present a new Skyrme-Hartree-Fock-Bogoliubov Nuclear-Mass model in which the contact-pairing force is constructed from microscopic pairing gaps of symmetric Nuclear matter and neutron matter calculated from realistic two- and three-body forces, with medium-polarization effects included. With the pairing being treated more realistically than in any of our earlier models, the rms deviation with respect to essentially all the available Mass data falls to 0.581 MeV, the best value ever found within the mean-field framework. Since our Skyrme force is also constrained by the properties of pure neutron matter, this new model is particularly well suited for application to astrophysical problems involving a neutron-rich environment, such as the elucidation of the r process of nucleosynthesis, and the description of supernova cores and neutron-star crusts.
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Nuclear Mass formulas for astrophysics
Nuclear Physics, 2006Co-Authors: J.m. Pearson, Stéphane GorielyAbstract:Abstract We review the Hartree–Fock–Bogolyubov Mass models of the Brussels–Montreal group and compare their suitability for astrophysical purposes with three other modern Mass formulas: the FRDM of Moller et al., the KUTY model of Koura et al., and the Duflo–Zuker 1995 model. In addition to considering the quality of their respective fits to the data of the atomic Mass evaluation of December 2003, we also compare their extrapolations out towards the neutron drip line. The implications for fission barriers and the role of the equation of state of neutron matter are both discussed.
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Nuclear Mass predictions within the skyrme HFB theory
Nuclear Physics, 2003Co-Authors: M. Samyn, Stéphane Goriely, J.m. PearsonAbstract:To increase the reliability of Nuclear Mass predictions for exotic neutron-rich nuclei we go beyond the recent HFBCS-1 Mass formula and present a second new Mass formula based on the Hartree-Fock-Bogoliubov (HFB) method.
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A Hartree-Fock Nuclear Mass formula
The European Physical Journal A, 2002Co-Authors: J.m. Pearson, Stéphane Goriely, M. SamynAbstract:We recall the main features of the recently published Mass formula, HFBCS-1, based on the Hartree-Fock-BCS method, and compare its extrapolations out to the neutron drip line with those given by the fine-range droplet model. A new Hartree-Fock-Bogolyubov Mass formula, HFB-1, is described: the rms error of the fit to 1888 Masses is 0.766 MeV, compared with 0 .738 MeV for HFBCS-1, but there are no substantial changes in the predictions relevant to the r-process. After a critical examination of various questions relating to the effective nucleon Mass and to the requirements of the relativistic mean-field theory, we conclude that the greatest remaining ambiguity concerns the nature of the pairing force.
G W F Drake - One of the best experts on this subject based on the ideXlab platform.
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Oscillator strengths for spin-changing P–D transitions in He I including the effect of a finite Nuclear Mass and intermediate coupling1
Canadian Journal of Physics, 2017Co-Authors: Donald C Morton, G W F DrakeAbstract:We have calculated the electric dipole (E1) oscillator strengths and spontaneous decay rates for 12 spin-changing P–D transitions of atomic helium. We included the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron. The specific transitions for 4He are n1P1o−n′3D1,2 and n3P1,2 o−n′1D2 with n = 2, 3, 4 and n′ = 3, 4. To include the effects of intermediate coupling between pure LS and jj, we used the Breit formulation for the spin–orbit and spin–other-orbit operators and combined the results of the exact diagonalization of the 2 × 2 energy matrix with pseudostate expansions to perform the perturbation sums over intermediate states. We calculated both the length and velocity gauges as a check on numerical accuracy and the validity of the transition operators.
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Oscillator strengths for 1s2 1S0–1s2p 3P1,2 transitions in helium-like carbon, nitrogen and oxygen including the effects of a finite Nuclear Mass
Journal of Physics B, 2016Co-Authors: Donald C Morton, G W F DrakeAbstract:We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for the spin-changing transitions of helium-like C v, N vi and O vii. We added the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron including an extra term derived by Pachucki. For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on numerical accuracy and the validity of the transition operators. There is some cancellation in the corrections for the Nuclear Mass and the electron anomaly so that if one is included the other should not be ignored
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oscillator strengths and radiative decay rates for spin changing s p transitions in helium finite Nuclear Mass effects
Journal of Physics B, 2014Co-Authors: Donald C Morton, Eva Schulhoff, G W F DrakeAbstract:We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for 24 spin-changing transitions of atomic helium. We included the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron augmented by the recently derived Pachucki term. The specific transitions for 4He are and with and for For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on both numerical accuracy and validity of the transition operators. The corrections for the Nuclear Mass and the electron anomaly tend to cancel, indicating that if one is included, then so should be the other. The tables give Mass- and anomaly-dependent coefficients permitting the easy generation of results for the other isotopes of helium.
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Oscillator strengths and radiative decay rates for spin-changing S–P transitions in helium: finite Nuclear Mass effects
Journal of Physics B, 2014Co-Authors: Donald C Morton, Eva Schulhoff, G W F DrakeAbstract:We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for 24 spin-changing transitions of atomic helium. We included the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron augmented by the recently derived Pachucki term. The specific transitions for 4He are and with and for For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on both numerical accuracy and validity of the transition operators. The corrections for the Nuclear Mass and the electron anomaly tend to cancel, indicating that if one is included, then so should be the other. The tables give Mass- and anomaly-dependent coefficients permitting the easy generation of results for the other isotopes of helium.
Krzysztof Pachucki - One of the best experts on this subject based on the ideXlab platform.
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Nuclear Mass corrections to the Casimir-Polder interaction
Physical Review A, 2016Co-Authors: Grzegorz Łach, Krzysztof PachuckiAbstract:We present a derivation of the finite Nuclear Mass corrections to the Casimir-Polder interaction between two atomic systems in the ground state. Equivalently, we show how the long-range asymptotics of the adiabatic correction is modified due to the finite speed of light. We show that in addition to the contribution resulting from the finite-Mass correction to atomic polarizabilities, a further contribution exists.
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Finite Nuclear Mass corrections to electric and magnetic interactions in diatomic molecules
Physical Review A, 2010Co-Authors: Krzysztof PachuckiAbstract:In order to interpret precise measurements of molecular properties, finite Nuclear Mass corrections to the Born-Oppenheimer approximation have to be accounted for. It is demonstrated that they can be obtained systematically using nonadiabatic perturbation theory. The formulas for the leading corrections to the relativistic contribution to energy, the transition electric dipole moment, the electric polarizability, and the magnetic shielding constant are derived. They can be conveniently calculated for a fixed position of nuclei, as in the Born-Oppenheimer approximation, and then averaged over the rovibrational function.
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relativistic qed and Nuclear Mass effects in the magnetic shielding of h3e
Journal of Chemical Physics, 2009Co-Authors: Adam Rudzinski, Mariusz Puchalski, Krzysztof PachuckiAbstract:The magnetic shielding σ of H3e is studied. The complete relativistic corrections of order O(α2), leading QED corrections of order O(α3 ln α), and finite Nuclear Mass effects of order O(m/mN) are calculated with high numerical precision. The resulting theoretical predictions for σ=59.967 43(10)×10−6 are the most accurate to date among all elements and support the use of H3e as a NMR standard.
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relativistic qed and finite Nuclear Mass corrections for low lying states of li and be
Physical Review A, 2008Co-Authors: Mariusz Puchalski, Krzysztof PachuckiAbstract:Accurate results for nonrelativistic energy, relativistic, QED, and finite Nuclear Mass corrections are obtained for $2^1S_{1/2}$, $3^1S_{1/2}$ and $2^1P_{1/2}$ states of the Li atom and Be$^+$ ion. Our computational approach uses the Hylleraas basis set with the analytic integration and recursion relations. From comparison of experimental results for the isotope shifts to theoretical predictions including Nuclear polarizabilities, we obtain Nuclear charge radii for Li and Be isotopes.
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Relativistic, QED, and finite Nuclear Mass corrections for low-lying states of Li and Be +
Physical Review A, 2008Co-Authors: Mariusz Puchalski, Krzysztof PachuckiAbstract:Accurate results for nonrelativistic energy, relativistic, QED, and finite Nuclear Mass corrections are obtained for $2^1S_{1/2}$, $3^1S_{1/2}$ and $2^1P_{1/2}$ states of the Li atom and Be$^+$ ion. Our computational approach uses the Hylleraas basis set with the analytic integration and recursion relations. From comparison of experimental results for the isotope shifts to theoretical predictions including Nuclear polarizabilities, we obtain Nuclear charge radii for Li and Be isotopes.
F Tondeur - One of the best experts on this subject based on the ideXlab platform.
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a hartree fock Nuclear Mass table
Atomic Data and Nuclear Data Tables, 2001Co-Authors: Stéphane Goriely, F Tondeur, J.m. PearsonAbstract:Abstract We present the first complete Nuclear Mass table, HFBCS-1, to be based on the Hartree–Fock–BCS method. The force used, MSk7, is a 10-parameter Skyrme force, along with a 4-parameter δ-function pairing force and a 2-parameter phenomenological Wigner term. Our tabulation presents 9200 nuclei, including all those lying between the drip lines over the range Z, N≥8 and Z≤120. The root-mean-square error of our fit to the 1888 nuclei in this range for which measured Masses are given in the 1995 Audi–Wapstra compilation is 0.738 MeV. In addition to the calculated Masses, we show the calculated neutron- and proton-separation energies, and beta-decay energies. We also give for each nucleus in the table the calculated values for the deformation parameters and deformation energy (with axial and left–right symmetry assumed), and for the charge radius.
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Nuclear Mass formula via an approximation to the hartree fock method
Atomic Data and Nuclear Data Tables, 1995Co-Authors: Y Aboussir, J.m. Pearson, A.k. Dutta, F TondeurAbstract:Abstract We present the first Nuclear Mass table to be based entirely on microscopic forces. The calculations are performed using the extended Thomas—Fermi plus Strutinsky integral method, a semiclassical approximation to the Hartree—Fock method that includes full Strutinsky shell corrections; BCS pairing corrections are added. The eight active parameters of the underlying Skyrme and δ-function pairing forces are fitted to all the 1492 Mass data (1988 compilation) for A ⩾ 36; the rms error of this fit is 0.736 MeV. Our tabulation covers the range 36 ⩽ A ⩽ 300 and reaches beyond the neutron- and proton-drip lines. In addition to the calculated Masses, we show the calculated neutron- and proton- separation energies and beta-decay energies. We also give for each nucleus in the table the model predictions for the deformation parameters and deformation energy at equilibrium (with axial and left-right symmetry assumed) and for the charge radii.
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Thomas-Fermi approach to Nuclear-Mass formula (IV). The ETFSI-1 Mass formula
Nuclear Physics, 1992Co-Authors: Y Aboussir, J.m. Pearson, A.k. Dutta, F TondeurAbstract:Abstract We summarize the main features of the first Nuclear-Mass table to be based entirely on microscopic interactions. A semi-classical approximation to the HF-BCS method is adopted, with full Strutinsky shell corrections included. The 9 parameters of the underlying Skyrme and δ-function pairing forces are fitted to all 1492 Mass data for A ⩾ 36; the r.m.s. error of this fit is 0.730 MeV. Our tabulation covers the range 36 ⩽ A ⩽ 300, goes out to the neutron-drip line and extends beyond the proton-drip line. Equilibrium deformations of all nuclei are calculated, with axial symmetry assumed. We also calculated several fission barriers using the same force with no further adjustment of parameters; a satisfactory agreement with experiment is obtained.
Donald C Morton - One of the best experts on this subject based on the ideXlab platform.
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Oscillator strengths for spin-changing P–D transitions in He I including the effect of a finite Nuclear Mass and intermediate coupling1
Canadian Journal of Physics, 2017Co-Authors: Donald C Morton, G W F DrakeAbstract:We have calculated the electric dipole (E1) oscillator strengths and spontaneous decay rates for 12 spin-changing P–D transitions of atomic helium. We included the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron. The specific transitions for 4He are n1P1o−n′3D1,2 and n3P1,2 o−n′1D2 with n = 2, 3, 4 and n′ = 3, 4. To include the effects of intermediate coupling between pure LS and jj, we used the Breit formulation for the spin–orbit and spin–other-orbit operators and combined the results of the exact diagonalization of the 2 × 2 energy matrix with pseudostate expansions to perform the perturbation sums over intermediate states. We calculated both the length and velocity gauges as a check on numerical accuracy and the validity of the transition operators.
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Oscillator strengths for 1s2 1S0–1s2p 3P1,2 transitions in helium-like carbon, nitrogen and oxygen including the effects of a finite Nuclear Mass
Journal of Physics B, 2016Co-Authors: Donald C Morton, G W F DrakeAbstract:We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for the spin-changing transitions of helium-like C v, N vi and O vii. We added the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron including an extra term derived by Pachucki. For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on numerical accuracy and the validity of the transition operators. There is some cancellation in the corrections for the Nuclear Mass and the electron anomaly so that if one is included the other should not be ignored
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oscillator strengths and radiative decay rates for spin changing s p transitions in helium finite Nuclear Mass effects
Journal of Physics B, 2014Co-Authors: Donald C Morton, Eva Schulhoff, G W F DrakeAbstract:We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for 24 spin-changing transitions of atomic helium. We included the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron augmented by the recently derived Pachucki term. The specific transitions for 4He are and with and for For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on both numerical accuracy and validity of the transition operators. The corrections for the Nuclear Mass and the electron anomaly tend to cancel, indicating that if one is included, then so should be the other. The tables give Mass- and anomaly-dependent coefficients permitting the easy generation of results for the other isotopes of helium.
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Oscillator strengths and radiative decay rates for spin-changing S–P transitions in helium: finite Nuclear Mass effects
Journal of Physics B, 2014Co-Authors: Donald C Morton, Eva Schulhoff, G W F DrakeAbstract:We have calculated the electric dipole (E1) and magnetic quadrupole (M2) oscillator strengths and spontaneous decay rates for 24 spin-changing transitions of atomic helium. We included the effects of the finite Nuclear Mass and the anomalous magnetic moment of the electron augmented by the recently derived Pachucki term. The specific transitions for 4He are and with and for For the E1 calculations we used the Breit approximation and pseudostate expansions to perform the perturbation sums over intermediate states in both the length and velocity gauge as a check on both numerical accuracy and validity of the transition operators. The corrections for the Nuclear Mass and the electron anomaly tend to cancel, indicating that if one is included, then so should be the other. The tables give Mass- and anomaly-dependent coefficients permitting the easy generation of results for the other isotopes of helium.
