Calculation of the spectroscopic constants for the electronic states A1Σ u+ , B1Πu, C1Πu, D1Σ u+ , and E1Σ u+ of the cesium dimer

The vibrational, rotational, and centrifugal distortion constants have been calculated for the electronic states A ¹Σ _u ⁺ , B ¹Π_u, C ¹Π_u, D ¹Σ _u ⁺ , and E ¹Σ _u ⁺ of the Cs₂ molecule. The calculation was performed on the basis of the semiempirical potential energy curves constructed in this paper. The calculated spectroscopic constants are compared with the experimental data. Original Russian Text ? A.D. Smirnov, 2007, published in Optika i Spektroskopiya, 2007, Vol. 102, No. 1, pp. 23–27.     

23 excitation of Li+ by electron impact

The 1¹S→2³S excitation of Li⁺ has been studied in the Coulomb-Born-Oppenheimer approximation. The differential and the total cross sections are given at double the threshold energy.     

Transition densities between the 01+, 21+, 41+, 02+, 22+, 11− and 31− states in 12C derived from the three-alpha resonating-group wave functions

All the multipole transition densities between the seven T = 0 states in ¹²C are calculated with the use of the microscopic 3α resonating-group wave functions which are obtained by dynamically solving the 3α relative motion with the total antisymmetrization taken into account exactly. The observed elastic and inelastic electron scattering form factors for the transition to the 2₁⁺, 4₁⁺, 0₂⁺, 1₁^?and 3₁^? states are well reproduced with no additional effective charge. The existence of a deformed intrinsic state for the 0₁⁺, 2₁⁺and 4₁⁺states is deduced by the analysis of the transition densities between them which are derived by the weak-coupling-type 3α wave functions; the intrinsic density distribution is illustrated. The monopole density distribution of the 0₂⁺, 2₂⁺ and 1₁^?, states is found to be much longer ranged than that of the 0₁⁺, 2₁⁺ and 4₁⁺ states; the 3₁^? state case is intermediate. On the basis of the transition densities between the 0₁⁺, 2₁⁺, 0₂⁺ and 2₂⁺ states, analysis is made of the transition between the shell-like states and the molecule-like states with a large spatial-structure change. Specific, effective nucleon-nucleon interactions are folded into the transition densities here obtained. The evident dependence of the radial shape of the folded nucleon-¹²C form factors on the choice of the interactions and the multi-step form factors for the excitation of the 0₂⁺, 1₁^? and 3₁^? states are discussed.     

Modeling of N2+ first negative spectra excited by electron impact on N2

Previously published intensity formulas for the calculation of N₂⁺ first negative spectra excited by electron impact on N₂ given by Herzberg and Muntz are generalized and adapted to arbitrary N₂X vibrational temperatures. The formulation includes all the quantities necessary for detailed computer modeling. Despite the refinements, the rotational structure and band profiles generated by the different methods agree to within a few percent at both normal (300°K) and elevated (5000°K) rotational and vibrational temperatures. Discrepancies in published A-values are noted and a recalculated array is given.     

Vibrational intensity distributions for the various electronic states of O2+, N2+ and CO+ produced by photoionization

The vibrational intensity distributions produced by the process of photoionization are tabulated as a function of wavelength between 745 and 304 Å for all major electronic states of O₂⁺, N₂⁺ and CO⁺. The technique of photoelectron spectroscopy was used with an electron energy analyzer of known luminosity.     

Properties of the adiabatic energy curves for the ground states of H2+, HD+, and D2+

Equilibrium internuclear distances, energies, and force constants are reported for the diatomic molecules H₂⁺, HD⁺, and D₂⁺ at the adiabatic level of approximation. The differences between these values and those calculated previously at the Born-Oppenheimer level of approximation are analyzed.     

Measurement of the branching ratios for Kμ2+, Kπ2+, Ke3+ and Ke3+ decays using a magnetic spectrometer with streamer chambers

The momenta of ～30 000 charged particles from K⁺ decays were measured using a magnetic spectrometer with streamer chambers. The ratio R = Γ(K_π2⁺)/Γ(K_μ2⁺) = 0.3355 ± 0.0057 was obtained. Our values for the branching ratios are: (63.18±0.43)% for K_μ2⁺, (21.18±0.33)% for K_π2⁺, (3.33±0.51)% for K_μ3⁺, (4.99±0.54)% for K_e3⁺.     

H1+,H2+,H3+和He,Ne,Ar碰撞过程中的巴耳末系Hα,Hβ,Hγ发射

实验利用TN-1710光学多道分析系统(OMA),对H₁⁺,H₂⁺,H₃⁺和He,Ne,Ar碰撞过程中产生的巴耳末系H_α,H_β,H_γ发射进行了测量,入射离子H₁⁺,H₂⁺,H₃⁺的 关键词：     

Stereodynamics of the reactions Ne+H2+/Ne+D2+/Ne+T2

The vector correlations between products and reagents for the reactions Ne+H + 2 , Ne+D + 2 , and Ne+T + 2 are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lü et al. [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections (2π/σ)(dσ 00 /dω t ), (2π/σ)(dσ 20 /dω t ), (2π/σ)(dσ 22+ /dω t ), and (2π/σ)(dσ 21 /dω t ), and the distributions of P (θ r ), P (φ r ), and P (θ r ,φ r ) are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed.     

Improved measurement of theB0 andB+ meson lifetimes

The lifetimes of theB ⁰ andB ⁺ mesons have been measured with theAleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991–1994. In the first of three methods, semileptonic decays ofB ⁰ andB ⁺ mesons were partially reconstructed by identifying events containing a lepton with an associatedD*⁻ or meson. The second method used fully reconstructedB ⁰ andB ⁺ mesons. The third method, used to measure theB ⁰ lifetime, employed a partial reconstruction technique to identifyB ⁰→D*⁻ π ⁺ X decays.     

Deperturbation of the N2+ first negative group B2Σu+-X2Σg+

Twelve bands of the N₂⁺B²Σ_u⁺-X²Σ_g⁺ system, including v_B = 0–6 and v_X = 0–8, are reanalyzed. All effects of B²Σ_u⁺ ～ A²Π_u perturbations are explicitly considered. Despite the use of high precision (0.01 cm^?1) line measurements, no evidence for a perturber other than A²Π_u is obtained. Deperturbed constants for the B²Σ_u⁺ and X²Σ_g⁺ states are derived. The deperturbation is shown to be self-consistent and complete (excluding effects of the C²Σ_u⁺ state) by examining semiempirical relationships of the perturbation matrix elements with the spin-rotation constants of the B and X states and atomic spin-orbit parameters. A number of previous analyses of transitions involving the v_B = 3 and 5 levels are found to be incorrect.     

Dissociative excitation of the fluoromethanes by electron impact

Emission spectra following electron impact on molecules of the homologous series of fluoromethanes CH_xF_4-x with x=0-4 have been investigated from the near infrared at 700 nm to the ultraviolet VUV-spectral region at 100 nm. Earlier experimental data for the visible and ultraviolet spectral region were revised and evaluated again on the basis of reliable new data for the dynamic viscosity of the molecules. The measurement of absolute and relative cross-sections were systematically extended into the VUV region from 100 nm to 200 nm. The examination of atomic lines as well as molecular band systems in the VUV gives further insight into the dissociation mechanism and shows that many excited levels even of atomic and molecular species cannot be populated directly, but only by transitions from higher-lying energy levels. Simple steric effects can be distinguished from more complex transition phenomena. Received: 25 February 1998 / Revised: 29 May 1998 and 18 June 1998 / Accepted: 23 June 1998     

Postcollision interaction upon electron excitation of 4sns1S0, 3S1 and 4snd1D2, 3DJ levels of zinc atom

The optical excitation functions (OEFs) for four series of spectral lines of the Zn atom at the transitions 4sn ₁ s ¹ S ₀ → 4s4p ¹ P ₁^∘ (n ₁ = 6–10), 4sn ₂ s ³ S ₁ → 4s4p ³ P ₂^∘ (n ₂ = 6−8), 4sn ₃ d ¹ D ₂ → 4s4p ¹ P ₁^∘ (n ₃ = 4−6), 4sn ₄ d ³ D _{1, 2, 3} → 4s4p ³ P ₂^∘ (n ₄ = 4−7) excited by a monoenergetic (0.04–0.08 eV) electron beam with energies from the excitation threshold to 18–19 eV are measured. In the energy dependences of the excitation cross sections, the effect of post-collision interaction of slow (scattered) and fast (emitted after the autoionization state decay) electrons is observed and described. This interaction leads to the capture of a slow electron into the listed discrete levels and the appearance of maxima in the excitation functions. The energies of the maxima are used to determine the energies and widths of single autoionization states or their groups by approximate formulas of the classical approach. The autoionization levels of the zinc atom responsible for the maxima observed are determined. Possible transfer of the orbital angular momentum between electrons is analyzed.     

Electron impact excitation of Fe25+

A three-state close-coupling calculation of the impact excitation of the 2s and 2p states of the hydrogenic ion Fe²⁵⁺ has been performed using the algebraic variational method.     

电子与类铍N3+和O4+离子碰撞激发截面的相对论扭曲波计算

采用全相对论扭曲波方法,系统地计算了类铍N³⁺和 O⁴⁺离子从基态到2s2p和2p² 的各激发态以及从亚稳态到2p²各激发态的电子碰撞激发截面,详细地讨论了靶态的关联效应对激发截面的影响.结果表明：对于2s-2p的单电子激发,在低能碰撞时,靶态的电子关联效应起非常重要的作用,且使得激发截面降低;而高能碰撞时,靶态波函数的描述对连续态波函数的影响比较小,对激发截面影响也比较小.对于2s²-2p²的双电子激发,其中基态2s²¹S₀到J=0的2p²³P₀,¹S₀的激发截面较大,其主要原因是末离子态波函数与基组态波函数的混合,但是其他几个激发的激发截面较小. 关键词： 全相对论扭曲波方法 电子碰撞激发 电子关联效应     

Search for T violation in the decays K+ → π0μ+ν and K+ → μ+νγ

Recent advances in a search for a T-violating transverse muon polarization in the decays K ⁺ → π ⁰ μ ⁺ ν and K ⁺ → μ ⁺ νγ in the on-going E246 experiment at KEK are reported. Future prospects in polarization measurements are also discussed. From Yadernaya Fizika, Vol. 65, No. 2, 2002, pp. 269–273. Original English Text Copyright ? 2002 by Kudenko. This article was submitted by the author in English.     

高速H2+离子轰击C靶诱发二次电子的发射行为与入射角的关系

运用Monte-Carlo方法结合半经验理论研究了高速H2+离子轰击C靶诱发二次电子的发射行为与入射角的关系。分别研究了电子发射产额与入射角以及发射统计性与入射角的关系。结果表明，由于H2+上的价电子的影响使得背向电子发射产额不遵守余弦倒数关系。斜入射时候的前向与背向电子产额的比值跟正入射时的情况不同。电子的发射统计跟入射角没有关系。标志偏离Poission分布的值 b，随入射能量的增加而增大。     

Rotational cooling efficiency upon molecular ionization: the case of Li2(a3Σu+) and Li2+(X2Σg+) interacting with 4He

The low-temperature (up to about 100 K) collisional (de)excitation cross sections are computed using the full coupled-channel (CC) quantum dynamics for both Li₂ and Li₂ ⁺ molecular targets in collision with ⁴He. The interaction forces are obtained from fairly accurate ab initio calculations and the corresponding pseudo-rates are also computed. The results show surprising similarities between sizes of inelastic flux distributions within final states in both systems and the findings are connected with the structural change in the molecular rotor features when the neutral species is replaced by its ionic counterpart.