Laser spectroscopic studies of state-dependent collisional quenching of the lifetimes of metastable antiprotonic helium atoms

M. Hori, H. A. Torii, R. S. Hayano, T. Ishikawa, F. E. Maas, H. Tamura, B. Ketzer, F. J. Hartmann, R. Pohl, C. Maierl, M. Hasinoff, T. Von Egidy, M. Kumakura, N. Morita, I. Sugai, D. Horváth, E. Widmann, J. Eades, T. Yamazaki

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

A laser spectroscopic method was developed to directly observe the lifetimes of individual states in metastable antiprotonic helium atoms (p̄ 4He+). Collisional effects with surrounding helium atoms were studied in cryogenic gas targets at pressures between 0.1 and 9.0 bars and at temperatures between 5.5 and 7.0 K. The metastable state (n, l) = (39,35) showed a lifetime of 1.5 μs, regardless of density, whereas the lifetime of the energetically lower-lying state (37,34) was found to shorten from 1.3 to 0.1 μs with increasing density. The lifetimes of the states (38,34) and (36,33) were determined to be 10 ns and 5 ns, respectively, showing the effects of the internal Auger process. When extrapolated to zero density, the measured lifetimes agreed with the results of calculations for the radiative and Auger widths. Using the fact that the state (37,34) becomes short lived at high density, the resonance (38,35)→(37,34) at a wavelength of 529.62 nm was detected.

Original languageEnglish
Pages (from-to)1613-1627
Number of pages15
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Volume58
Issue number2
Publication statusPublished - Dec 1 1998

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Fingerprint Dive into the research topics of 'Laser spectroscopic studies of state-dependent collisional quenching of the lifetimes of metastable antiprotonic helium atoms'. Together they form a unique fingerprint.

  • Cite this

    Hori, M., Torii, H. A., Hayano, R. S., Ishikawa, T., Maas, F. E., Tamura, H., Ketzer, B., Hartmann, F. J., Pohl, R., Maierl, C., Hasinoff, M., Von Egidy, T., Kumakura, M., Morita, N., Sugai, I., Horváth, D., Widmann, E., Eades, J., & Yamazaki, T. (1998). Laser spectroscopic studies of state-dependent collisional quenching of the lifetimes of metastable antiprotonic helium atoms. Physical Review A - Atomic, Molecular, and Optical Physics, 58(2), 1613-1627.