Electric polarizabilities of four low-J even-parity states and three low-J
odd-parity states of atomic barium in the range 35,600 to $36,000\
cm^{-1}areinvestigated.Thestatesofinterestareexcited(inanatomicbeam)viaanintermediateodd−paritystatewithasequenceoftwolaserpulses.Theodd−paritystatescanbeexcitedduetotheStark−inducedmixingwitheven−paritystates.Thepolarizabilitiesaremeasuredviadirectspectroscopyonthesecond−stagetransition.Severalstateshavetensorandscalarpolarizabilitiesthatexceedthevaluesthatmightbeexpectedfromtheknownenergylevelsofbariumbymorethantwoordersofmagnitude.TwooftheStark−inducedtransitionscannotbeidentifiedfromtheknownenergyspectrumofbarium.Theobservationssuggesttheexistenceofasyetunidentifiedodd−parityenergystates,whoseenergiesandangularmomentaaredeterminedinthepresentexperiment.Atentativeidentificationofthesestatesas[Xe]6s8p
^3P_{0,2}$ is suggested.Comment: 29 pages, 12 figure
The results of ab initio calculation of E1 amplitudes, lifetimes,and
polarizabilities for several low-lying levels of ytterbium are reported. The
effective Hamiltonian for the valence electrons has been constructed in the
frame of CI+MBPT method and solutions of many electron equation are found.Comment: 11 pages, submitted to Phys.Rev.