Octupole contributions to the generalized oscillator strengths of discrete dipole transitions in noble-gas atoms

Journal Article · Fri Jun 15 04:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.75.062703· OSTI ID:20991138

Amusia, M Ya ^[1]; Chernysheva, L V ^[2]; Felfli, Z; Msezane, A Z ^[3]

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1. Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)
2. A. F. Ioffe Physical-Technical Institute, St. Petersburg 194021 (Russian Federation)
3. Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, Georgia 30314 (United States)

The generalized oscillator strengths (GOS's) of discrete excitations np{yields}nd and np{yields}(n+1)s,d, both dipole (L=1) and octupole (L=3), are studied. We demonstrate that although the relevant transitions in the same atom are closely located in energy, the dependence of their GOS's on the momentum transfer squared q{sup 2} is remarkably different; viz., the GOS's corresponding to L=3 have at least one extra maximum as a function of q{sup 2} and dominate over those of the L=1, starting from about q{sup 2}=1.5 a.u. Peculiarities are noted in the GOS of only the Ne dipole 2p{yields}3s transition in contrast to the rest of the atoms; viz., the characteristic minimum and the maximum are not obliterated by the dominance of 2p{yields}3d GOS dipole and octupole sum as in the other atoms. The depth of the minimum of the GOS for the dipole 2p{yields}3s transition is reduced considerably by the 2p{yields}3d dipole and octupole GOS sums, while the corresponding maximum is enhanced. In the GOS sum both the minimum and maximum are still identifiable, permitting experimental observation. The calculations were performed in the one particle Hartree-Fock (HF) approximation and with account of many-electron correlations via the random phase approximation with exchange (RPAE). The GOS's are studied for values of q{sup 2} up to 50 a.u. Our calculated RPAE GOS's for the Ar 3p{yields}4s dipole transition compare very well with the recently measured data of Zhu et al. [Phys. Rev. A 73, 042703 (2006)].

• OSTI ID: 20991138
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 75; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOMS
COMPARATIVE EVALUATIONS
DIPOLES
E1-TRANSITIONS
E3-TRANSITIONS
ELECTRON CORRELATION
EXCITATION
HARTREE-FOCK METHOD
HYDROFLUORIC ACID
MOMENTUM TRANSFER
NEON
OCTUPOLES
OSCILLATOR STRENGTHS
RANDOM PHASE APPROXIMATION