Measurement of absolute cross sections for excitation of the 3s(2)3p(5) 2P(o)(3/2)- 3s(2)3p(5) 2P(o)(1/2) fine-structure transition in Fe9+

Experimental cross sections are reported for the 3s(2)3p(5) 2P(o)(3/2)- 3s(2)3p(5) 2P(o)(1/2) transition in Fe9+ located at 1.945 eV. The center-of-mass interaction energies are in the range of 1.72 eV (below threshold) through threshold, to 5.6 eV (2.9 x threshold). Data are compared with results of a 49-state Breit-Pauli R-matrix theory. The experiment detects structures at 3.5 and 4.6 eV corresponding to enhancement of the direct excitation via many narrow, closely spaced resonances about these energies calculated by the theory. Iron is present in practically every astrophysical object, as well as being an impurity in fusion plasmas. Present data are the first electron-energy-loss measurements on a highly charged iron ion.     

Improved measurement of the 1s2s 1S0-1s2p 3P1 interval in heliumlike silicon

Using colinear fast-beam laser spectroscopy with copropagating and counter-propagating beams we have measured the 1s2s 1S0-1s2p 3P1 intercombination interval in 28Si12+ with the result 7230.585(6) cm{-1}. The experiment made use of a dual-wavelength, high-finesse, power build-up cavity excited by single-frequency lasers at 1319 and 1450 nm. The result will provide a precision test of ab initio relativistic many-body atomic theory at moderate Z.     

Cascading through the 1P1 (1s)(2p) state of fluorine

The ¹P₁ (1s)(2p) state of He-like fluorine produced in a foil-excited fluorine beam is shown to decay with a $\text{t}{}^{\mathrm{<mtext>-3</mtext><mtext>2</mtext>}}$ time function. This behavior is identical to that recently reported for oxygen beams and thus demonstrates that there is no strong Z dependence for this time behavior.     

Precise determination of the 2s(1/2)-2p(1/2) splitting in very heavy lithiumlike ions utilizing dielectronic recombination

The 2s(1/2)-2p(1/2) energy splittings DeltaE(L) of the lithiumlike ions 19779Au76+, 20882Pb79+, and 23892U89+ have been measured at the Experimental Storage Ring, utilizing low energy dielectronic recombination. The resonance energies in total 41 different 1s(2) 2p(1/2)nl(j(')) (n > or =20) autoionizing Rydberg states populated in the dielectronic capture process have been determined. The 2s(1/2)-->2p(1/2) excitation energies have been obtained by extrapolation of these resonance energies to the associated series limits n--> infinity. The combined analysis of the experimental data for all three ions yields DeltaE(L)=216.134(96) eV for Au76+, 230.650(81) eV for Pb79+, and 280.516(99) eV for U89+.     

类锂等电子系列(1s2p2p)~4 P~e和(1s2s2p)~4 P~0态的能量和精细结构研究

利用改进的马鞍点方法,截断变分方法,并考虑能量的相对论修正和质量极化效应,计算和研究了类理等电子系列的两个四重态（１ｓ２ｐ２ｐ）４Ｐ０和（１ｓ２ｓ２ｐ）４Ｐｅ态的精细结构和平均跃迁波长,并与实验和其它理论计算结果进行了比较。     

LiⅠ等电子序列[(1s2p)3P,4d]2P0及 [(1s2s)1S,5p]2P0自电离态的计算

利用鞍点复转动及全实加关联的方法,计算了LiⅠ等电子序列[(1s2p)3P,4d]2P0及[(1s2s)1S,5p]2P0自电离态的能量和宽度.计算结果中包括相对论修正和质量极化修正.文中讨论了自电离宽度随核电荷数Z的变化关系,同时也讨论了精细结构分裂值及相对论修正随核电荷数Z的变化关系.     

类铍离子磁四极M2 2s2 1S0—2s2p3P2 (Z=10—103)禁戒跃迁

利用全相对论多组态Dirac-Fock方法系统地计算了高离化类铍离子的磁四极M2 2s²¹S₀—2s2p³P₂ (Z=10—103)自旋禁戒跃迁的能级间隔、跃迁概率和振子强度，计算中考虑了重要核的有限体积效应，Breit修正和QED修正，所得结果和最近的实验数据以及理论值进行了比较，结果表明：高原子序数的高电荷离子(Z≥70)磁四极M2自旋禁戒跃迁几乎可以和中性原子的光学允许跃迁相比拟，不仅在天体等离子体中，在ICF和MCF高温激光等离子体中，磁四极自旋禁戒跃迁和其他自旋禁戒跃迁（磁偶极、电四极）一样不容忽视，在双电子复合、不透明度、自由程等理论计算中应该考虑其影响. 关键词： 磁四极M2 能级间隔 跃迁概率 振子强度     

类铍离子磁四极M2 2s2 1S0-2s2p 3 P2(Z=10-103)禁戒跃迁

利用全相对论多组态:Dirac-Fock方法系统地计算了高离化类铍离子的磁四极M2 2s2 1S0-2s2p3P2 (Z=10-103)自旋禁戒跃迁的能级间隔、跃迁概率和振子强度,计算中考虑了重要核的有限体积效应,Breit修正和QED修正,所得结果和最近的实验数据以及理论值进行了比较,结果表明:高原子序数的高电荷离子(Z≥70)磁四极M2自旋禁戒跃迁几乎可以和中性原子的光学允许跃迁相比拟,不仅在天体等离子体中,在ICF和MCF高温激光等离子体中,磁四极自旋禁戒跃迁和其他自旋禁戒跃迁(磁偶极、电四极)一样不容忽视,在双电子复合、不透明度、自由程等理论计算中应该考虑其影响.     

弛豫与关联效应对NII离子2s22p3s3P1—2s22p21D2与2s22p3s1P1—2s22p23P0,1,2自旋禁戒跃迁概率的影响

用多组态Dirac-Fock方法，并系统考虑相对论效应、电子关联、弛豫效应等重要贡献，计算了NII离子2s22p3s 3P1—2s22p21D2和2s22p3s 1P1—2s22p23P0,1,2自旋禁戒跃迁概率和振子强度-通过比较计算证实：弛豫和关联效应对禁戒跃迁概率的影响非常大，考虑了这些效应后，计算结果有显著的改善-由跃迁概率和振子强度的计算值推断，2s22p3s 3P1—2s22p21D2的谱线强度应该比原有的理论预言值小- 关键词： 跃迁概率 多组态Dirac-Fock方法     

Measurement of the nuclear magnetic moment of110Ag(T 1/2=24.4 s)

Nuclear magnetic resonance of¹¹⁰Ag has been observed in silver halides using the polarized neutron capture,β decay anisotropy method. The magnetic moment was determined asμ _I(¹¹⁰Ag)=2.7084 (5) nm (uncorrected).     

QED and hyperfine splitting in the 2s1/2−2p3/2 X-ray transition in lithium-like Bi80+

The measurement of the Bi⁸⁰⁺ 2s_1/2−2p_3/2 transition energy is discussed. The measurement resolved the hyperfine splitting of the (1s²2s) F=4,5 ground configuration and allowed a determination of the Lamb shift contributions with a precision of about 9 × 10^-4 providing the most accurate test of QED in a high-Z ion to date. This revised version was published online in July 2006 with corrections to the Cover Date.     

类硼离子N2+光电离的R-矩阵理论计算

本文首次运用R-矩阵理论方法,分别在单通道近似和三态密耦近似下计算了离子N2+基态(1s22s22p) 2P的不同过程、不同分波的光电离截面及各分波的光电离截面随有效量子数的变化规律.在三态密耦近似下,由于大量的自电离态与连续态的相互作用,计算结果显示了光电离过程中非常丰富的Rydberg系列共振结构,是以前的理论计算中所从未涉及到的.     

Relativistic electron correlation, quantum electrodynamics, and the lifetime of the 1s(2)2s(2)2p2p0(3/2) level in boronlike argon

The lifetime of the Ar13+ 1s(2)2s(2)2p2p0(3/2) metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electron-electron correlation effects like the frequency-dependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately shorter than our experimental result.     

Interference effects in the resonant photoemission channels to the Ne+ 2p(4)(1D2)3p 2P, 2D,and 2F states in the Ne 1s excitation region

We present measurements of total and partial photoionization cross sections of Ne in the 1s excitation region. The total cross section exhibits resonances with symmetric profiles, whereas the branching ratios to the Ne+ 2p(4)(1D2)3p 2P, 2D, and 2F states present strong oscillations in the interresonance regions. We prove that not only the interference between the direct and resonant ionization processes but also the interference among the ionization processes via different nonisolated resonances are important for this effect.     

Study of the rare decays B0-->D((*)+)(s)pi(-) and B0-->D((*)-)(s)K+

We report evidence for the decays B0-->D(+)(s)pi(-) and B0-->D(-)(s)K+ and the results of a search for B0-->D(*+)(s)pi(-) and B0-->D(*-)(s)K+ in a sample of 84 x 10(6) upsilon(4S) decays into BB pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage ring. We measure the branching fractions B(B0-->D(+)(s)pi(-))=[3.2+/-0.9(stat)+/-1.0(syst)] x 10(-5) and B(B0-->D(-)(s)K+)=[3.2+/-1.0(stat)+/-1.0(syst)] x 10(-5). We also set 90% C.L. limits B(B0-->D(*+)(s)pi(-))<4.1 x 10(-5) and B(B0-->D(*-)(s)K+)<2.5 x 10(-5).