一价铝离子能级结构的多通道量子亏损理论分析

利用多通道量子亏损理论(MQDT)对一价铝离子(AIII)的各受干扰序列:3sns ¹S₀,3snp ³P_0,1,2^O,¹P₁^O,3snd ¹D₂和3snf³F_2,3,4^O的能级结构进行理论分析。结果表明:前两个序列所受到的干扰较弱,后三个序列则受到了来自干扰态3p4s ¹P₁^O,3p^{2 1}D₂和3p3d³F_2,3,4^O的强烈干扰,而3snf ¹F₃^O序列则受到来自电离限上方干扰态的影响。利用获得的MQDT参数推算出3p3d ¹F₃^O干扰态位于电离限上方5613cm^-1处,这一结果与其他作者的预言相符合。 关键词：     

Dielectron widths of the <Emphasis Type="Italic">S</Emphasis>-, <Emphasis Type="Italic">D</Emphasis>-vector bottomonium states

The dielectron widths of Y(nS)(n = 1, …, 7) and vector decay constants are calculated using the relativistic string Hamiltonian with a universal interaction. For Y(nS) (n = 1, 2, 3) the dielectron widths and their ratios are obtained in full agreement with the latest CLEO data. For Y(10580) and Y(11020) a good agreement with experiment is reached only if the 4S-3D mixing (with a mixing angle θ = 27°± 4°) and 6S-5D mixing (with θ = 40°±5°) are taken into account. The possibility to observe higher “mixed D-wave” resonances, $ \tilde \Upsilon $ \tilde \Upsilon (n ³ D ₁) with n = 3, 4, 5 is discussed. In particular, $ \tilde \Upsilon $ \tilde \Upsilon (≈11120), originating from the pure 5³ D ₁ state, can acquire a rather large dielectron width, ∼130 eV, so that this resonance may become manifest in the e ⁺ e ⁻ experiments. On the contrary, the widths of pure D-wave states are very small, Γ _ee (n ³ D ₁)≤ 2 eV.     

Transition energies, wavelengths, oscillator strengths and transition probabilities between 1s, 1sns and 1snp (2?n?9) states for He-like Silicon

Multiconfiguration Hartree-Fock calculations with Breit-Pauli relativistic corrections are reported for electric dipole transition (E1) energies, wavelengths, weighted oscillator strengths and transition probabilities between all of the 1s², 1sns and 1snp (2?n?9) states for He-like silicon. The results are found to compare very well with available other results except Δn=0 due to differences in the calculated excitation energies.     

Precision measurements of optical excitation functions for zinc atom

The excitation of zinc atoms by ultramonoenergetic electrons is experimentally studied. The optical excitation functions for 19 atomic spectral lines that originate from the n ¹ S ₀, 4¹ P ₁, n ¹ D ₂, n ³ S ₁, 4³ P ₁, 6³ P ₂, and n ³ D _j levels are studied in detail. In the excitation functions measured from the excitation threshold to 19 eV for the spectral lines originating from the n ¹ S ₀, n ³ S ₁, n ¹ D ², and n ³ D _j levels, specific features caused by postcollision interactions of emitted and scattered electrons are observed for the first time in the energy region of 10.9–17.0 eV near the thresholds of autoionization states.     

Li“洞原子”高位三激发态~2S(m)和~2D(m)(m=2——7)的能级、精细结构和Auger宽度

采用鞍点变分方法和鞍点复数转动方法,考虑了相对论修正、质量极化修正等基础上,计算了L"i洞原子"高位三激发态2l2l′nl″2S(m)和2D(m)(m=2—7)高根系列的高精度波函数、相对论能量、精细结构,同时还计算了Auger分宽度和总宽度,通过相对论效应的讨论,对2S(7),2D(6)及2D(7)的组态进行了重新标定.     

Lasing conditions in recombining helium plasmas

Lasing conditions for He have been evaluated numerically. We have used a collisional radiative model to calculate overpopulation densities Δn_ij, which are defined as differences between population densities per unit statistical weight of the upper and lower excited levels i and j, respectively. Laser oscillations for the level pairs 2¹P-3¹S, 2¹P-4¹S, 2¹P-3¹D, 2¹P-4¹D, 3¹D-4¹F, 3¹P-4¹S, 3¹P-4¹D, and 3³P-4³S are possible when the electron densities are within well defined limits at low electron temperature (T_e = 0.1 eV). For level pairs of the singlet state, the inversion mechanism for He is the same as for H. Only collisional processes produce population inversion in the triplet level pair 3³P-4³S.     

The controlled excitation of forbidden transitions in the two-photon spectrum of strontium by using collisions and electric fields

We present experimental results involving controlled configuration mixing in two-photon spectroscopy of highly-excited states by exploiting a weak external electric field and collisions. The method has allowed new extensions to high members of the two-photon forbidden J = 3 odd-parity 5snf ¹F₃ and the J = 0, even-parity 5sns ¹S₀ Rydberg series of neutral strontium to be observed. We achieve resonant two-photon transverse excitation of a high density atomic jet by using a narrow bandwidth tunable dye laser in a heat pipe setup with sensitive ionization detection. Experimental term values are extended for the 5sns ¹S₀ series up to n = 46. By suitable exploitation of the composition and pressure of the buffer gases in conjunction with the electric field strength in the excitation region and the exciting laser beam intensity we have also extended observations up to n = 44 for the 5snf ¹F₃ series and up to n = 46 for the 5snp ¹P₁ series. Our results demonstrate a novel and remarkably simple experimental method to access high Rydberg states to which transitions are forbidden from the ground state by parity and other selection rules.     

Investigation of the mass dependence of self-diffusion coefficients by molecular dynamics calculations: binary and ternary isotopic mixtures of atoms

Extensive molecular dynamics calculations have been used to study for the first time systematically the dependence of the self-diffusion coefficients D_i (i = 1, 2, 3) in binary and ternary atomic isotopic mixtures on the particle mass ratios m*₂ = m ₂/m ₁ and m*₃ = m ₃/m ₁ at different reduced temperatures T* and reduced particle number densities n*, using a Lennard-Jones 12-6 potential and a hard-soft-spheres potential. In addition, the dependence of D_i values of binary mixtures on the mole fraction x ₁ = 1—x ₂ was also investigated for some thermodynamic states. The calculated values of D_i can be represented quantitatively by exponential estimates of the form D_i = D* _i (m*₂)^ex _i in the case of binary mixtures and D_i = D ⁰ _i (m*₂)^{ex _i} (m ₃)^{ext _i} in the case of ternary mixtures. D ⁰ _i are the self-diffusion coefficients in reference mixtures of mass ratios m*₂ = m*₃ = 1. The dependence of the exponents ex _i (m*₂, T*, n*, x ₁) of binary mixtures on m*₂, T*, n*, and x ₁ and the dependence of the exponents ext _i (m*₂, m*₃, n*) of equimolar ternary mixtures at T* = 1.8 on the exponents ex _i of the constituent binary mixtures and on m*₂, m*₃, and n* are discussed.     

Collisional redistribution of energy in the infrared spectrum of potassium vapor under two-photon excitation

The cascade decay of the 6S(4D) levels of the potassium atom, 6S(4D)-5P-5S(3D)-4P, following two-photon excitation of potassium vapor (4S-4P-6S) is investigated experimentally. The dependences of 11 resonant IR line intensities on potassium and buffer gas densities are presented. It is shown that the presence of buffer gas leads to collisional redistribution of radiation, causing suppression of some lines and production of new ones.     

The effect of the electric field on the spectral line shape

The effect of the external electric field on the spectral line shape under conditions of a uniform population of magnetic sublevels is studied in the density matrix formalism. The line shapes of spontaneous radiation for the atomic 4¹P₁-2¹S₀, 4³D₁-2³P₀, 4³S₁-2³P₀, 4³P₁-2³S₁, 4³D₁-2³P₁, and 4³S₁-2³P₁ transitions ofHe are calculated. The electric field is shown to be responsible for the spectral line shape asymmetry. Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 23–28, November, 1999.     

Elastic scattering and break-up processes in then-d system

A method to solve the AGS equations in momentum space is presented. The two-nucleon transition operators are generated with the new Bonn potential restricted to the states¹ S ₀,³ S ₁-³ D ₁,³ P ₀,¹ P ₁,³ P ₁,³ P ₂-³ F ₂,¹ D ₂ and³ D ₂. Cross sections and analyzing powers for elastic and break-up processes are calculated at a neutron laboratory energyE _n =10.3 MeV.     

Electron spin resonance identification of phosphorus-centred radicals in γ-irradiated dialkyl phosphites

Potential curves have been calculated by the ab initio MRD CI method for states of OH⁺ correlating with O(³ P, ¹ D, ¹ S) + H⁺ and O⁺(⁴ S, ² D, ² P) + H. Spectroscopic constants derived from the calculated potential curves are in good agreement with the available experimental data. The calculations support the experimental assignment of vibrational quantum numbers for levels perturbing the A ³Π state.     

New perovskite oxides LaBa<Emphasis Type="Italic">M</Emphasis>CoO<Subscript>5 + δ</Subscript> (<Emphasis Type="Italic">M</Emphasis> = Fe,Cu): Synthesis,structure, and properties

The electrical resistivity ρ and the thermopower S of ceramic materials LnBaCuFeO_{5 + δ} (Ln= La, Pr, Nd, Sm, Gd-Lu) are measured in air at temperatures in the range from 300 to 1100 K. All the studied ferrocuprates are p-type semiconductors. The electrical resistivity ρ and the thermopower S of these compounds increase with a decrease in the radius of the Ln ³⁺ cation (with an increase in the number of 4f electrons n in Ln ³⁺). The nonmonotonic behavior of the dependences ρ=f(n) and S=f(n) indicates that the electrical properties of the layered ferrocuprates LnBaCuFeO_{5 + δ} depend on the electronic configuration of the Ln ³⁺ cation. The power factors P calculated for the LnBaCuFeO_{5 + δ} ceramic materials from the experimental values of ρ and S increase with increasing temperature and, at T = 1000 K, reach the maximum values P = 102.0 and 54.1 μW m⁻¹ K⁻² for Ln = Pr(4f ²) and Sm(4f ⁵), respectively, and become close to each other and equal to 30–35 μW m⁻¹ K⁻² for Ln = Gd(4f ⁷), Dy(4f ⁹), and Ho(4f ¹⁰).     

Transition wavelengths for helium atom in weakly coupled hot plasmas

We have investigated the effect of surrounding plasmas on several singly excited and doubly excited meta-stable bound states of helium atom using highly correlated basis functions for singly excited S, P, D states and CI-type basis functions for doubly excited meta-stable D states. Plasma effect is taken care of by using a screened Coulomb (Yukawa) potential obtained from the Debye model that admits a variety of plasma conditions, and such a model plays an important role in plasma spectroscopy. The wavelengths for transitions from the 1snp ¹P° (n=2,3)→1s²¹S^e, 1snp ³P° (n=2,3)→1s2s ³S^e, 2pnp ¹P^e (n=3,4)→1s2p ¹P°, 2pnp ³P^e (n=2,3)→1s2p ³P°, 2pnd ¹D° (n=3,4)→1s3d ¹D^e, 2pnd ³D° (n=3,4)→1s3d ³D^e, 2p3p ¹P^e→2pnd ¹D° (n=3,4), 2pnd ¹D°(n=3, 4)→2p4p ¹P^e, 2pnp ³P^e (n=2,3)→2p3d ³D°, and 2pnp ³P^e (n=2,3)→2p4d ³D° of helium atom in plasmas for various Debye lengths are reported.     

D<Subscript>sJ</Subscript>(2860) and D<Subscript>sJ</Subscript>(2715)

Recently the Babar Collaboration reported a new cs̄ state, D_sJ(2860), and the Belle Collaboration observed D_sJ(2715). We investigate the strong decays of the excited cs̄ states using the ³ P ₀ model. After comparing the theoretical decay widths and decay patterns with the available experimental data, we are inclined to conclude that: (1) D_sJ(2715) is probably the 1^-(1³ D ₁) cs̄ state, although the 1^-(2³ S ₁) assignment is not completely excluded; (2) D_sJ(2860) seems unlikely to be the 1^-(2³ S ₁) and 1^-(1³ D ₁) candidate; (3) to consider D_sJ(2860) either as a 0⁺(2³ P ₀) or as a 3^-(1³ D ₃) cs̄ state is consistent with the experimental data; (4) the experimental search of D_sJ(2860) in the channels D_sη, DK^*, D^*K and D_s ^*η will be crucial to distinguish the above two possibilities. PACS 13.25.Ft; 12.39.-x     

Orientational order parameter studies on 3.Om and 3O.Om liquid crystals

Orientational order parameter S is evaluated in the nematic phase of six liquid crystal compounds, N-(p-n-propyl benzylidene)-p-n-alkoxy anilines, 3.Om and N-(p-n-propyloxy benzylidene)-p-n-alkoxy anilines, 3O.Om compounds with m = 6, 7 and 8, using different methods. The techniques employed are S from birefringence δn, Haller's approximation from (1?T/T_c) ^β, effective geometry parameter α_g and Vuks’ scaling factor S_C. The values of S obtained using the above methods are compared with one another and with the results on a number of liquid crystals; the liquid crystals favor isotropic Vuks’ method.     

Collisional — Radiative Model of Helium Plasma. II. Global Population Coefficients

We present results of our calculation of global population coefficients based on a collisional — radiative model of the helium plasma. The results are given for 2³P, 2¹P, 3³S, 3¹S, 3³P, 3¹D, 3³D, 3¹P, 4³ and 4¹ states of helium atoms. We consider electron densities from 10⁷ to 10¹⁸ cm^?3 and electron temperature from 1 to 10 eV. The electron distribution function is considered to be Maxwellian and the plasma to be radiatively thin.     

The hyperfine splittings in heavy-light mesons and quarkonia

Hyperfine splittings (HFS) are calculated within the Field Correlator Method, taking into account relativistic corrections. The HFS in bottomonium and the B _q (q = n, s) mesons are shown to be in full agreement with experiment if a universal coupling α _HF = 0.310 is taken in perturbative spinspin potential. It gives M(B*) −M(B) = 45.7(3) MeV, M(B _s ^* ) − M(B _s ) = 46.7(3) MeV (n _f = 4), while in bottomonium Δ_HF(b $ \bar b $ \bar b ) = M(Υ(9460)) − M(η _b (1S)) = 63.4 MeV for n _f = 4 and 71.1 MeV for n _f = 5 are obtained; just the latter agrees with recent BaBar data. For unobserved excited states we predict M(Υ(2S))−M(η _b (2S)) = 36(2)MeV,M(Υ(3S))−M(η _b (3S)) = 28(2)MeV, and also M(B _c ^*) = 6334(4) MeV, M(B _c (2S)) = 6868(4) MeV, M(B _c ^* (2S)) = 6905(4) MeV. The mass splittings between D(2³ S ₁) − D(2¹ S ₀), D _s (2³ S ₁) − D _s (2¹ S ₀) are predicted to be ∼75 MeV, which are significantly smaller than in several other studies but agree with the mass splitting between recently observed D(2533) and D*(2610).     

Excited high spin states of novel π conjugated verdazyl radicals: photoinduced spin alignment utilizing the excited molecular field

This paper reports the excited quartet (S = 3/2) and quintet (S = 2) states arising from the intramolecular radical-triplet pair in the purely organic π conjugated spin systems. A previous paper reported the excited quartet and quintet states of 9-anthracene-(4-phenyliminonitroxide) and 9,10-anthracene-bis(4-phenyliminonitroxide), respectively, in which iminonitroxide radicals are linked to the phenyl- or diphenylanthracene moiety (a spin-coupler) through the π conjugation. The similar excited quartet and quintet states were observed for the 9-anthra-cene-(4-phenylverdazyl) radical (1) and 9,10-anthracene-bis(4-phenylverdazyl) diradical (2) by time resolved electron spin resonance (TRESR). The TRESR spectrum was analysed by the ordinary spin Hamiltonian with the Zeeman and fine structure terms. For the quartet state of 1, the g value, fine structure splitting, and relative population of the Ms sublevels have been determined to be g = 2.0035, D = 0.0230 cm^?1, E = 0.0, P _1/2′ = P _?1/2′ = 0.5 and P _3/2′ = P _?3/2′ = 0.0, respectively, by spectral simulation. The spin Hamiltonian parameters of the quintet state of 2 were determined to be g = 2.0035, D = 0.0128 cm^?1, E = 0.0, P _2′ = P _?2′ = 0.0, P _1′ = P _?1′ = 0.37 and P _0′ = 0.26, respectively. Direct observation of the excited high spin state showed that photoinduced intramolecular spin alignment is realized between the excited triplet state (S = 1) of the phenyl- or diphenylanthracene moiety and the doublet spin (S = 1/2) of the dangling verdazyl radicals. Ab initio MO calculations (DFT) were carried out in order to clarify the mechanism of the photoinduced spin alignment.