| 1. |
- Dalgarno, Alex, et al.
(author)
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Collisions of H and Hbar
- 2001
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In: New Directions in Antimatter Chemistry and Physics. - : Kluwer Academic Publishers. - 0792371526 ; , s. 47-52
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Book chapter (peer-reviewed)
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| 2. |
- Forrey, Robert C., et al.
(author)
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Nonadiabatic coupling in cold collisions of spin-polarized metastable hydrogen atoms
- 2007
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In: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 76:5, s. 052709-
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Journal article (peer-reviewed)abstract
- Previous calculations of low-temperature cross sections for collisions between spin-polarized metastable hydrogen atoms are improved to include nonadiabatic radial and angular coupling at large interatomic separations. The electrostatic dipole-quadrupole interaction produces nonadiabatic radial coupling between (2s,2p) and (2p,2p) states, while the Coriolis interaction produces nonadiabatic angular coupling. Both of these long-range contributions are handled in a space-fixed atomic gauge that is particularly convenient for a spin-polarized system. The improved theoretical results are compared with an existing experiment.
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| 3. |
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| 4. |
- Forrey, Robert, et al.
(author)
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Collisions between metastable hydrogen atoms at thermal energies
- 2000
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 85:20, s. 4245-4248
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Journal article (peer-reviewed)abstract
- The complex interaction potentials arising in the approach of two metastable hydrogen 2s atoms are calculated and the cross sections for ionization, excitation transfer, and elastic scattering are predicted. The measured cross section for associative ionization at E = 4.1 meV equals 2×10-15 cm2. We calculate a total ionization cross section of 2×10-13 cm2, varying as E-2/3 at higher energies. Thus it appears that dissociative ionization is the major ionization channel. We find also that double excitation transfer into two excited H(2p) atoms is still more probable with the large cross section of 9×10-12 cm2 at E = 4.1 meV varying as E-1/2 at higher energies. The detection of the resulting Lyman alpha photons would provide a diagnostic test of our predictions.
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| 5. |
- Froelich, Piotr, et al.
(author)
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Antihydrogen in Interaction with Atoms and Surfaces
- 2005
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In: AIP Conference Proceedings. - : AIP. - 0094-243X .- 1551-7616. ; 770:1, s. 51-67, s. 51-67
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Journal article (pop. science, debate, etc.)abstract
- Anoverview of the antiatom interactions with matter is given inthe context of the ongoing efforts to trap and coolantihydrogen at CERN. We show how the atom-antiatom scattering can,in addition to annihilation, result in a number of collisionalreactions such as elastic scattering, rearrangement to protonium and positronium,and even radiative association leading to formation of unusual short-livedatom-antiatom molecules. We also show that sufficiently cold antiatoms canbe reflected from material walls. The rates for these reactionsare of interest for the experiments with antihydrogen atoms atCERN, they probe the feasibility of collisional cooling of antihydrogenand they contribute to the understanding of stability of matterin contact with antimatter in general.
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| 6. |
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| 7. |
- Froelich, Piotr, et al.
(author)
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Hydrogen : Antihydrogen Molecule and its Properties
- 2004
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In: Few-body systems. - : Springer Science and Business Media LLC. - 0177-7963 .- 1432-5411. ; 34:1-3, s. 63-72
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Journal article (peer-reviewed)abstract
- The metastability of the four-body system is discussed from the point of view of radiative rearrangement collisions of the hydrogen and antihydrogen. Such collisions lead to the formation of an intermediate molecular state which further decays into positronium and protonium or is destroyed via annihilation. We present calculations of the lifetime of the system and the branching ratios for Coulombic decay and annihilation.
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| 8. |
- Froelich, Piotr, et al.
(author)
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Hydrogen - Antihydrogen Collisions
- 2001
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In: Nuclear Physics A. - 0375-9474 .- 1873-1554. ; 692:1-2, s. 182c-183c
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Journal article (peer-reviewed)
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| 9. |
- Froelich, Piotr, et al.
(author)
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Hydrogen-antihydrogen collisions
- 2000
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 84:20, s. 4577-4580
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Journal article (peer-reviewed)abstract
- Matter-antimatter interactions are investigated using hydrogen-antihydrogen collisions as an example. Cross sections for elastic scattering and for the antihydrogen loss (either through the rearrangement reaction, resulting in formation of protonium and positronium according to H+H →pp+1 e+e-, or via annihilation in flight) are calculated for the first time in a fully quantum mechanical approach. Implications for experiments intending to trap and cool antihydrogen are discussed.
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| 10. |
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