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Title: Annihilation of electron-positron pairs in the positronium ion Ps{sup -} and bipositronium Ps{sub 2}

Journal Article · · Physical Review. A
 [1]
  1. Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada)

Rates of the two-, three-, four-, and five-photon annihilations of the electron-positron pairs are determined numerically for the three-body positronium ion Ps{sup -}(e{sup -}e{sup +}e{sup -}) and four-body bipositronium ''molecule''Ps{sub 2}(e{sup -}e{sup +}e{sup -}e{sup +}). The values obtained in our computations are {gamma}{sub 2{gamma}}(Ps{sup -}){approx_equal}2.080 485 305 25x10{sup 9} s{sup -1}, {gamma}{sub 3{gamma}}(Ps{sup -}){approx_equal}5.636 415 155 0x10{sup 6} s{sup -1}, {gamma}{sub 4{gamma}}(Ps{sup -}){approx_equal}3.075x10{sup 3} s{sup -1}, {gamma}{sub 5{gamma}}(Ps{sup -}){approx_equal}5.383 s{sup -1}, and {gamma}{sub 2{gamma}}(Ps{sub 2}){approx_equal}4.438 595 2x10{sup 9} s{sup -1}, {gamma}{sub 3{gamma}}(Ps{sub 2}){approx_equal}1.202 497x10{sup 7} s{sup -1}, {gamma}{sub 4{gamma}}(Ps{sub 2}){approx_equal}6.562x10{sup 3} s{sup -1}, {gamma}{sub 5{gamma}}(Ps{sub 2}){approx_equal}11.484 s{sup -1}. The four- and five-photon annihilation rates are significantly smaller than the corresponding two- and three-photon annihilation rates known for these systems. We also determine the rates of one- and zero-photon annihilation for the Ps{sup -} ion and Ps{sub 2} system. The corresponding numerical values are {gamma}{sub 1{gamma}}(Ps{sup -}){approx_equal}3.824 91x10{sup -2} s{sup -1}, {gamma}{sub 1{gamma}}(Ps{sub 2}){approx_equal}1.941 88x10{sup -1} s{sup -1}, and {gamma}{sub 0{gamma}}(Ps{sub 2}){approx_equal}2.321 97x10{sup -9} s{sup -1}.

OSTI ID:
21313363
Journal Information:
Physical Review. A, Vol. 80, Issue 1; Other Information: DOI: 10.1103/PhysRevA.80.014502; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English