Relativistic corrections for one- and two-photon matrix elements of weakly bound systems

1987 ◽  
Vol 98 (5) ◽  
pp. 621-642 ◽  
Author(s):  
M. De Sanctis ◽  
D. Prosperi
Keyword(s):  
Matrix Elements ◽  
Weakly Bound ◽  
Two Photon ◽  
Relativistic Corrections

scholarly journals Pathways for intramolecular relaxation in S 1 benzene

1990 ◽  
Vol 332 (1625) ◽  
pp. 189-201 ◽  
Keyword(s):  
Energy Coupling ◽  
Weak Limit ◽  
Excess Energy ◽  
Matrix Elements ◽  
Strong Limit ◽  
Decay Channels ◽  
Two Photon ◽  
Decay Behaviour ◽  
Quantum Numbers ◽  
Fast Electronic

Sub-Doppler spectra of various one- and two-photon vibronic bands of benzene are discussed and analysed to determine the pathways of intramolecular relaxation for Sx benzene. New results are presented for the 14J1q16| band of C 6 H 6 and the 14^1^ band of 13 C 6 H 6 . The decay behaviour depends strongly on the excess energy and the rotational quantum numbers rather than on the vibrational character and symmetry of the excited state. At low vibrational excess energy the pathway for intramolecular relaxation is a coupling in the strong limit between pairs of states in Sx leading to shifts of lines, whereas at intermediate excess energy coupling in the weak limit to background states in Sx is present. These background states are strongly broadened due to a fast electronic non-radiative process. The intramolecular relaxation is found to be initiated by the coupling to the broadened S 1 background states and energy can flow via these states to the T 1 or S 0 state. The rotationally selective disappearance of lines is believed to be due to an intricate interplay of the rotational dependence of the coupling matrix elements and accidental resonances, which lead to interference of possible decay channels.

scholarly journals Free-free matrix-elements for two-photon opacity

2020 ◽  
Vol 34 ◽  
pp. 100717
Author(s):  
R. More ◽  
J.-C. Pain ◽  
S.B. Hansen ◽  
T. Nagayama ◽  
J.E. Bailey
Keyword(s):  
Matrix Elements ◽  
Two Photon

scholarly journals Many-body calculations of two-photon, two-color matrix elements for attosecond delays

2019 ◽  
Vol 100 (4) ◽  
Author(s):  
Jimmy Vinbladh ◽  
Jan Marcus Dahlström ◽  
Eva Lindroth
Keyword(s):  
Matrix Elements ◽  
Many Body ◽  
Two Photon

Relativistic corrections to He I transition ratesThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 129-134 ◽  
Author(s):  
Donald C. Morton ◽  
Paul Moffatt ◽  
G. W.F. Drake
Keyword(s):  
Nuclear Charge ◽  
Wave Functions ◽  
Oscillator Strengths ◽  
Matrix Elements ◽  
Nuclear Mass ◽  
Atomic Systems ◽  
Relativistic Corrections ◽  
Doubly Excited ◽  
Accurate Wave ◽  
The Continuum

The relativistic corrections to the theoretical oscillator strengths of light elements such as helium are typically less than 0.1% and usually are ignored. However, they can be important for comparisons with the most accurate experiments, and they rapidly increase in magnitude with increasing nuclear charge. We have begun with the spin-forbidden electric-dipole transitions of neutral helium, using calculations consisting of (1) extremely accurate wave functions without relativistic corrections for both infinite and finite nuclear mass, (2) spin-changing matrix elements through the perturbations of the wave functions by the spin-orbit and spin-other-orbit Breit operators, (3) the use of pseudostates in the sums over all the intermediate states including the continuum, and (4) the inclusion as perturbers of the 1S0 and 3S1 states the pseudostates corresponding to the doubly excited npn′p 3P 0e and npn′p 1P 1e terms, respectively. As examples of these calculations, we present oscillator strengths for the transitions 1 1S0–2 3P1, 2 1S0–2 3P1, 2 3S1–2 1P1, 2 1P1–3 3D1,2, and 2 3P1,2–3 1D2.

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