Gerade/ungerade symmetry- breaking in HD at the n =2 dissociation limit
We report on a study of the I'1Πg outer well state of HD. Via a resonance-enhanced XUV + IR (extreme ultraviolet + infrared) excitation scheme, rovibronic levels (v = 0-2, J = 1-4) are populated and probed by pulsed lasers. Level energies are measured with an accuracy of 0.03 cm-1. Due to gerade-ungerade symmetry breaking, the long-range behavior of the I' potential in HD deviates from that of H2 and D2. When this deviation is taken into account a semi-empirical potential for the I'1Πg state may be constructed, resulting in better agreement with the observed level energies than derived from an adiabatic ab initio potential. With this new potential it is predicted that the I' well can sustain only 4 vibrational levels, with the v = 3 level having a binding energy of 1.38(3) cm-1. PACS Nos.: 33.80.Rv, 34.20.Cf, 33.20.Ni, 31.50.+w
Near-threshold continuum structure and the dissociation energies of H2, HD, and D2.
Using laser double-resonance spectroscopy, we have studied the second dissociation limit of all three stable isotopic variants of molecular hydrogen. Just above threshold, the vibrational continuum exhibits considerable fine-grained structure, differing greatly between isotopes because of varying nonadiabatic couplings between the [ital B], [ital B][prime], and [ital C] states. Significantly improved values of the dissociation energies are obtained from the continuum onsets. We also report preliminary investigations of atomic 2[ital S]:2[ital P] branching ratios very near threshold.
Drug Testing in Public Agencies: Are Personnel Directors Doing Things Right?
The results of a survey of 300 public agencies personnel directors are reported. The report describes the drug and alcohol testing policies and procedures now used by these respondents. The implications of the survey results are evaluated in terms of critical issues of personnel management practice and public policy: (1) the protection of employees' constitutional rights, (2) the public's right to an effective public service, and (3) management's need to reduce liability risks and to increase program effectiveness.