Higher nuclear electric multipole moments

The total electrostatic interaction energy between a nucleus, with charge density distribution p(r), and surrounding charged particles (electrons and other nuclei) is given by 

The use of extended nuclear charge density distributions, instead of the simple point-like Dirac delta distribution, is almost a standard in present- 

Finally, in Sect. 6, we have briefly given some examples for physical properties or effects, which involve the nuclear charge density distribution or the nucleon distribution in a more direct way, such that the change from a point-like to an extended nucleus is not unimportant. These include the electron-nucleus Darwin term, QED effects like vacuum polarization, and parity non-conservation due to neutral weak interaction. Hyperfine interaction, i.e., the interaction between higher nuclear electric (and magnetic) 

Taylor, The fundamental physical constants, Phys. Today 48 (8/II) (1995) BG9-BG13. 

Physical reference data were taken from the web site maintained by the NIST, reachable at the URL http //physics.ni8t.gov/Phy8RefData/contents.html. 

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In this last section we mention a few cases, where properties other than the energy of a system are considered, which are influenced in particular by the change from the point-like nucleus case (PNC) to the finite nucleus case (FNC) for the nuclear model. Firstly, we consider the electron-nuclear contact term (Darwin term), and turn then to higher quantum electrodynamic effects. In both cases the nuclear charge density distribution p r) is involved. The next item, parity non-conservation due to neutral weak interaction between electrons and nuclei, involves the nuclear proton and neutron density distributions, i.e., the particle density ditributions n r) and n (r). Finally, higher nuclear electric multipole moments, which involve the charge density distribution p r) again, are mentioned briefly. 

In sections 2.7, 2.10, and 2.11 we have expanded the radiation fields of an arbitrary charge distribution by the use of simple and direct methods. This technique is adequate for a discussion of excited atoms since only the electric dipole, and occasionally the magnetic dipole and electric quadrupole terms are significant. However, in nuclear physics higher-order terms are frequently required and it is clear that a more general and powerful technique should be used. In this method the charge distribution is expanded in terms of its multipole moments and the radiation fields are constructed from spherical waves which have well-... 

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