TY - JOUR
T1 - Time-Dependent Coupled-Channel Calculations of the Annihilation Rate in Positron-Hydrogen Collisions
AU - Yamanaka, Nobuhiro
AU - Kino, Yasushi
PY - 2003
Y1 - 2003
N2 - We calculate the positron annihilation rate in positron-hydrogen collisions for positron energies of 250 meV-6.5 eV using a time-dependent coupled channel method. A semiempirical model recently proposed in Phys. Rev. Lett. 79 (1997), 2241 predicts that the annihilation rate prominently enhances through virtual positronium formation as the positron energy approaches the positronium formation threshold (6.8 eV) from 4 eV. We illustrate time evolution of wave functions to show that such a prominent enhancement of the annihilation rate is not found and contribution of virtual positronium formation is not important below 6.5 eV.
AB - We calculate the positron annihilation rate in positron-hydrogen collisions for positron energies of 250 meV-6.5 eV using a time-dependent coupled channel method. A semiempirical model recently proposed in Phys. Rev. Lett. 79 (1997), 2241 predicts that the annihilation rate prominently enhances through virtual positronium formation as the positron energy approaches the positronium formation threshold (6.8 eV) from 4 eV. We illustrate time evolution of wave functions to show that such a prominent enhancement of the annihilation rate is not found and contribution of virtual positronium formation is not important below 6.5 eV.
KW - Positron annihilation
KW - Time-dependent coupled channel method
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U2 - 10.1023/B:HYPE.0000004249.30972.f6
DO - 10.1023/B:HYPE.0000004249.30972.f6
M3 - Article
AN - SCOPUS:0346363851
SN - 0304-3843
VL - 146-147
SP - 337
EP - 341
JO - Hyperfine Interactions
JF - Hyperfine Interactions
IS - 1-4
ER -