TY - JOUR
T1 - Laser spectroscopy of metastable states in the [Formula Presented] cascade of antiprotonic [Formula Presented]
AU - Hartmann, F. J.
AU - Ketzer, B.
AU - Maierl, C.
AU - Pohl, R.
AU - von Egidy, T.
AU - Hayano, R. S.
AU - Hori, M.
AU - Ishikawa, T.
AU - Tamura, H.
AU - Torii, H. A.
AU - Kumakura, M.
AU - Morita, N.
AU - Sugai, I.
AU - Horváth, D.
AU - Eades, J.
AU - Widmann, E.
AU - Yamazaki, T.
PY - 1998
Y1 - 1998
N2 - The pressure dependence of the metastable-state lifetimes in antiprotonic [Formula Presented] atoms [Formula Presented] was studied using the recently observed laser resonance transition [Formula Presented] in the [Formula Presented] cascade. To this end antiprotons from the Low Energy Antiproton Ring (LEAR) at CERN were extracted in approximately 200-ns-long bunches with about [Formula Presented] per bunch and stopped in a [Formula Presented] gas target. Time spectra of delayed annihilation products were taken with the help of a Čerenkov counter with a gated photomultiplier. Under our experimental conditions, [Formula Presented] and [Formula Presented] the lowest metastable level [Formula Presented] was found to be much shorter lived than the corresponding state (37,34) in the [Formula Presented] cascade of [Formula Presented] It was strongly quenched at pressures above 500 mbars, whereas the higher states in the cascade remained nearly unaffected. This enabled us to investigate the [Formula Presented] transition by resonant laser deexcitation. Its wavelength was found to be [Formula Presented] only 6 ppm lower than the theoretical value given by Korobov and Bakalov [Phys. Rev. Lett. 79, 3379 1997)] after including relativistic corrections.
AB - The pressure dependence of the metastable-state lifetimes in antiprotonic [Formula Presented] atoms [Formula Presented] was studied using the recently observed laser resonance transition [Formula Presented] in the [Formula Presented] cascade. To this end antiprotons from the Low Energy Antiproton Ring (LEAR) at CERN were extracted in approximately 200-ns-long bunches with about [Formula Presented] per bunch and stopped in a [Formula Presented] gas target. Time spectra of delayed annihilation products were taken with the help of a Čerenkov counter with a gated photomultiplier. Under our experimental conditions, [Formula Presented] and [Formula Presented] the lowest metastable level [Formula Presented] was found to be much shorter lived than the corresponding state (37,34) in the [Formula Presented] cascade of [Formula Presented] It was strongly quenched at pressures above 500 mbars, whereas the higher states in the cascade remained nearly unaffected. This enabled us to investigate the [Formula Presented] transition by resonant laser deexcitation. Its wavelength was found to be [Formula Presented] only 6 ppm lower than the theoretical value given by Korobov and Bakalov [Phys. Rev. Lett. 79, 3379 1997)] after including relativistic corrections.
UR - http://www.scopus.com/inward/record.url?scp=0032209423&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032209423&partnerID=8YFLogxK
U2 - 10.1103/PhysRevA.58.3604
DO - 10.1103/PhysRevA.58.3604
M3 - Article
AN - SCOPUS:0032209423
VL - 58
SP - 3604
EP - 3610
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
SN - 1050-2947
IS - 5
ER -