Comment on ''Laboratory measurements and theoretical calculations of O{sub 2} A-band electric quadrupole transitions''
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)
D. A. Long et al.[Phys. Rev. A 80, 042513 (2009)] recently reported accurate measurements on the ultraweak electric quadrupole (E2) transitions in the O{sub 2} A band. They also presented elegant theoretical calculation of the line intensities based on Hund's case (b) formulation. However, their theoretical elucidation fails to relate to a highly relevant previous work by Balasubramanian and Narayanan [Acta Phys. Hung 74, 341 (1994)] in which closed-form expressions for the E2 branch line strengths for the eight possible rotational branches of the b{sup 1}{Sigma}{sub g}{sup +}-X{sup 3}{Sigma}{sub g}{sup -} transition, in intermediate coupling, are derived. The complete equivalence of the two methods is proven through direct calculation. A second point of concern is that the magnetic dipole (M1) transition moment M{sub 1} = 0.0687 {mu}{sub B} deduced by Long et al. from the previously measured transition intensities is {approx}2.7 times the ab initio value of 0.0255 {mu}{sub B} computed by Minaev et al.[Chem. Phys. 208, 299 (1996)]. Since the latter reproduces closely the measured Einstein's spontaneous emission coefficient of the A band, this large discrepancy is intriguing.
- OSTI ID:
- 22095508
- Journal Information:
- Physical Review. A, Vol. 84, Issue 5; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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