ISSN:
1434-6079
Keywords:
PACS. 36.10.-k Exotic atoms and molecules (containing mesons, muons, and other unusual particles) – 42.62.Fi Laser spectroscopy – 34.20.Gj Intermolecular and atom-molecule potentials and forces
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: The quenching of metastable states of antiprotonic helium by collisions with hydrogen and deuterium molecules was studied. A systematic investigation of the delayed annihilation time spectra at various H2 and D2 admixture ratios at the ppm level revealed characteristic changes of their shape, which indicated a strong principal and orbital quantum number dependent quenching of levels in both cases. Applying a laser spectroscopy technique to measure the lifetimes of individual states and cascades we deduced H2 and D2 quenching cross-sections for the states (n, l )= (39, 35) and (37, 34). These cross-sections establish for D2 molecules the strong increase of the quenching efficiency with increasing principal quantum number n of the state under investigation previously reported for the case of H2 admixtures. Our experiments indicate that the low-n state (37, 34) is somewhat less affected by D2 than by H2, while the high-n state (39, 35) is equally quenched by both isotopes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s100530170246
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