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- Gustavsson, Martin G H, et al.
(författare)
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The Atomic Nucleus
- 2003
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Ingår i: "Handbook of Molecular Physics and Quantum Chemistry". - : Wiley. ; , s. 477-484
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- As molecules and heavy atoms get invoked for studies of fundamental interactions and properties, the demand for more accurate descriptions of the wavefunction within and close to the nucleus grow more stringent. With the generally increasing precision of quantum chemistry calculations, the simple point-nucleus approximation, resulting in the well-known Z=r potential, is no longer completely adequate. The inadequacy becomes more and more evident as quantum chemistry takes on the challenge of molecules including heavy, or even superheavy, atoms: For large Z, the behaviour close to the nucleus becomes too singular for a point nuclear charge, and for the|still hypothetical|case of Z > 137, the Dirac equation breaks down. For finite nuclear distributions, the possible range extends much further. Many properties depend on details of the nuclear structure. What are the alternatives for the nuclear distributions used in calculations? What are their advantages and disadvantages from a computational point of view? How should calculated results be presented in order to make possible meaningful comparisons between results obtained using different approaches? How much is known experimentally and how is that information best included in the calculations? These are a few of the questions addressed in this chapter. This chapter focuses mainly on the distribution of charge, which, however influences also other properties.
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- Mårtensson-Pendrill, Ann-Marie, 1952
(författare)
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Calculation of a P-and T-nonconserving weak interaction in Xe and Hg with many-body perturbation theory
- 1985
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 54:11, s. 1153-
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Tidskriftsartikel (refereegranskat)abstract
- The electronic part of a possible P- and T-nonconserving neutral-weak-current-induced electric dipole moment in atomic Xe and Hg was calculated with many-body perturbation theory. After the effects of this P- and T-nonconserving interaction on all core orbitals were treated self-consistently, thereby including all single-particle effects to all orders but no correlation effects, the results μe=(5.2×10−23e m)CTσN and μe=−(6.0×10−22e m)CTσN, respectively, were obtained for Xe and Hg. The value for Xe can be combined with the recent experimental result, ∣∣μe(Xe129)∣∣
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- Mårtensson-Pendrill, Ann-Marie, 1952
(författare)
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Hyperfine structure in the 4d states of Rb-like Sr
- 2002
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Ingår i: J. Phys. B: At. Mol. Opt. Phys.. - 0953-4075. ; 35:4, s. 917-924
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Tidskriftsartikel (refereegranskat)abstract
- Relativistic coupled-cluster calculations are presented for the low-lying states of the Rb-like ion 87Sr+, of interest as a possible frequency standard. The resulting constants for the magnetic hyperfine stucture were: A(5s) = -1000 MHz, A(5p1/2) = -177 MHz, A(5p3/2) = -35 MHz, A(4d3/2) = -47 MHz and A(4d5/2) = + 1 MHz. As a result of the abnormally small A factor for the 4d5/2 state, the electric and magnetic hyperfine structures are comparable for that state. Electronic factors for the electric hyperfine structure were evaluated for the states with j>1, giving B(5p3/2)/Q = 271 MHz b-1, B(4d3/2)/Q = 115 MHz b-1 and B(4d5/2)/Q = 160 MHz b-1. The calculated B/Q value for the 5p3/2 state was combined with experimental B factors for the isotope sequence 79-93Sr, giving revised values for the nuclear quadrupole moments.
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- Mårtensson-Pendrill, Ann-Marie, 1952, et al.
(författare)
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The atomic nucleus : Atomkärnan
- 2003
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Ingår i: Handbook of Molecular Physics and Quantum Chemistry. - : Wiley. ; , s. 477-484
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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- Mårtensson-Pendrill, Ann-Marie, 1952
(författare)
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The Manhattan Project - a part of physics history
- 2006
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Ingår i: Physics Education. - 0031-9120. ; 41:6, s. 493-501
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Tidskriftsartikel (refereegranskat)abstract
- Current physics textbooks tend to exclude military applications, but it is explained here how a study of the Manhattan project—the devastatingly successful attempt to develop an atomic bomb—can show students how the lives and work of physicists are shaped by events in society. Much of the original source material is available in books and on the internet (and referenced here), which allows students to discover the views of the scientists for themselves.
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