The two-photon approximation for the four-photon decay of the 4d excited state in hydrogenThis 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.

Labzowsky, L. N.

doi:10.1139/p10-073

Cited by 2 publications

(4 citation statements)

References 21 publications

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“…Two-photon emission processes were evaluated accurately in [25][26][27]. In our recent works [28,29], three-and four-photon transitions with separation out of the two-photon links were considered from the astrophysical point of view. In [30,31] we considered one-and two-photon transitions in external electric fields.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the electromagnetically induced transparency in the era of cosmological hydrogen recombination

Дубрович

Plunien

2012

J. Phys. B: At. Mol. Opt. Phys.

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Investigation of the cosmic microwave background formation processes is one of the most actual problem at present time. In this paper we analyze the response of the hydrogen atom to the external photon fields. Field characteristics are defined via conditions corresponding to the recombination era of universe. Approximation of three-level atom is used to describe the "atom -fields" interaction. It is found that the phenomena of the electromagnetically induced transparancy (EIT) takes place in this case. Consideration of EIT phenomena makes it necessary to update astrophysical description of the processes of the cosmic microwave background formation and, in particular, Sobolev escape probability. Additional terms to the optical depth entering in the Sobolev escape probability are found to contribute on the level about 1%.

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Section: Introductionmentioning

confidence: 99%

Investigation of the electromagnetically induced transparency in the era of cosmological hydrogen recombination

Дубрович

Plunien

2012

J. Phys. B: At. Mol. Opt. Phys.

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“…In [34,35], it was suggested that the multiphoton transitions which contain cascades with the two-photon links can also contribute to the radiation 'escape' in the process of cosmological recombination. This approach was called 'twophoton approximation' since the contribution of the 'pure' multiphoton transitions with more than two photons was neglected.…”

Section: Contribution Of the Three-photon Transitionsmentioning

confidence: 99%

“…As in the case of three-photon decays, we neglect the contribution of the 'pure' four-photon decays and consider only the cascade contributions with two-photon links, namely 4s → 3p + γ (E1) → 2s + 2γ (E1) → 1s + 4γ (E1), 4s → 3s + 2γ (E1) → 2p + 3γ (E1) → 1s + 4γ (E1) and 4s → 3p + γ (E1) → 2p + 3γ (E1) → 1s + 4γ (E1). Then the expression similar to equation ( 40) arises [34,35]:…”

Section: Radiation 'Escape' In the Four-photon Transitionsmentioning

confidence: 99%

“…Similarly, W (1γ ) 3p,2s ≡ (1γ ) 3p,2s and 3p is defined by equation ( 41). The two-photon differential transition rate (frequency distribution) dW (2γ ) 4s,3s can be obtained from equations ( 17) and (18) with the replacement 2s → 4s, 1s → 3s and the value of the decay rate magnitude can be found in [35,39]. Then the radiation 'escape' via the four-photon transition 4s → 1s + 4γ (E1) is…”

Section: Radiation 'Escape' In the Four-photon Transitionsmentioning

confidence: 99%

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QED model of the radiation escape from matter

Zalialiutdinov¹,

Labzowsky²

2012

J. Phys. B: At. Mol. Opt. Phys.

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A simple model based on QED is presented for the estimation of contribution of the excited level few-photon decays to the radiation escape from the matter in the epoch of the cosmological hydrogen recombination. It is shown that apart from the widely studied two-photon decays, some specific 3-photon decays can contribute on the level of 0.1% accuracy, required by the recent astrophysical observations. I. INTRODUCTIONTheory of the cosmological hydrogen recombination became one of the most intensively discussed fundamental physics problems in the last decade. The interest comes from the accurate measurements of the asymmetry in the temperature and polarization distribution of the Cosmic Microwave Background (CMB) [1], [2]. The launching of the Planck Surveuor which enables to perform these measurements with accuracy 0.1% makes the situation even more intriguing.The modern theory of the cosmological hydrogen recombination starts from the papers by Zel'dovich, Kurt and Sunyaev [3] and by Peebles [4]. It was argued that the bound-bound one-photon transitions from the upper levels to the lower ones did not permit the hydrogen atoms to reach their ground states: each photon released in such transition in one atom was immediately absorbed by another atom. These reabsorption processes did not allow the radiation to "escape" the interaction with the matter. As it was first established in [3], [4] the two-photon 2s-1s transition presents the main channel for the radiation "escape" and formation of the CMB. This transition also led to the final hydrogen recombination. Hence, the recent properties of the CMB are essentially defined by the two-photon processes during the cosmological recombination epoch.In [5] the importance of the two-photon decays from excited states with n > 2 for the detailed analysis of the properties of CMB was noted. Over the past few years the theory of cosmological recombination was essentially detalized by many authors. In particular, in [5], [6] it was demonstrated that the two-photon transitions ns → 1s(n > 2) and nd → 1s can also give a sizeable contribution to the radiation "escape". There is a difference between the decay of ns(n > 2), nd states and the decay of the 2s state. This difference is due to the presence of cascade transitions as the dominant decay channels in the cases of ns(n > 2) and nd levels. For the 2s level the cascade transitions are absent. The cascade photons can be effectively reabsorbed and therefore the problem of separation of the "pure" two-photon emission from the cascade photons arises in connection with the "escape" probability. This problem was intensively discussed during the last decade [7]- [12]. As it was proved in [11] the separation of the "pure" two-photon emission for the ns(n > 2) and nd levels is an ambiguous procedure. First this ambiguity was established for the two-photon transitions with cascades in the highly charged ions [13]. To reach the level of accuracy 0.1% for the theoretical description of the properties of the CMB many effects should be taken ...

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The two-photon approximation for the four-photon decay of the 4d excited state in hydrogenThis 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.

Cited by 2 publications

References 21 publications

Investigation of the electromagnetically induced transparency in the era of cosmological hydrogen recombination

Investigation of the electromagnetically induced transparency in the era of cosmological hydrogen recombination

QED model of the radiation escape from matter

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