激发双模压缩真空态的非经典特性

通过数值计算研究了激发双模压缩真空态a^+mb^+m|ξ>的非经典特性.结果表明:对于a^+mb^+m|ξ>,Cauchy-Schwartz不等式受到破坏;当取适当的压缩参量r(例如0.4～0.7)时,a^+mb^+m|ξ>呈现出正交分量的压缩和光子的亚泊松分布,而且压缩程度和亚泊松特性都随m的增大而有所增强.     

四态叠加多模光场的等幂次N次方H压缩

根据量子力学中的线性叠加原理,构造了由奇、偶相干态光场所组成的一种新型的四态叠加多模叠加态光场|Ψ_o,e⁽⁴⁾Ⅲ〉_q.它是由多模虚奇相干态和多模虚偶相干态这两者的线性叠加所组成的.利用多模压缩态理论详细研究了态|Ψ_o,e⁽⁴⁾Ⅲ〉_q的等幂次N次方H压缩特性.结果发现:当腔模总数q与压缩次数N的乘积为奇数时,若各模初始相位和qj＝1φ_j、态间叠加几率幅γ_o、γ_e以及态间相位差θ_e-θ_o等相关参量满足一定的不同条件时,态|Ψ_o,e⁽⁴⁾Ⅲ〉_q可分别呈现以下非经典效应:i)等幂次N次方H压缩;ii)"半相干态"效应.     

Li2分子自旋一致激发态a3Σ+u和b3Πu的分析势能函数的从头算

使用对称性匹配簇-组态相互作用方法首次计算了Li₂分子自旋一致激发态a³Σ⁺_u和b³Π_u的离解能、平衡几何及其谐振频率。使用最小二乘法、利用Murrell-Sorbie函数形式拟合出了Li₂分子三重态的第一激发态a³Σ⁺_u 和第二激发态b³Π_u的完整势能函数，并计算了这两个态的光谱常数 (B_e, α_e, ω_e 和 ω_eχ_e) 和力常数 (f₂, f₃和f₄)。得到了Murrell-Sorbie函数形式既适用于基态、又适用于激发态的结论。将计算得到的激发态（a³Σ⁺_u和b³Π_u）的离解能、平衡几何及其谐振频率与实验结果及其它理论计算结果进行了比较。从比较的结果中可以清楚地看出，本文的计算结果在计算精度方面有很大的改进。     

态|Ψ(3)>q中广义电场分量的偶数次N次方Y压缩

构造了由多模复共轭虚相干态、多模复共轭虚相干态的相反态和多模复共轭相干态的线性叠加所组成的一种新型的三态叠加多模叠加态光场|Ψ⁽³⁾>_q.利用多模压缩态理论,研究了态|Ψ⁽³⁾>_q中广义电场分量的偶数次等幂次N次方Y压缩特性.结果发现:态|Ψ⁽³⁾>_q是一种典型的三态叠加多模非经典光场;当压缩次数N等于2P且P为2m’+1(m’=0,1,2,…,…)时,如果各模的初始相位φ_j(j=1,2,3,…,…,q)、态间的初始相位差(θ₁-θ₂)、(θ₁-θ₃)和(θ₂-θ₃),以及各单模相干态光场的总的平均光子数等分别满足各自的取值条件,则在这种情况下态|Ψ⁽³⁾>_q的广义电场分量可呈现出偶数次的广义非线性等幂次2(2m’+1)次方Y压缩效应.     

Profiles of (υ′;υ″ = 0) bands recorded in excitation spectra using b30+u ← X10g+ transitions in Cd2 and B31 ← X10+ transitions in CdAr

Profiles of the (υ′;υ ^″ = 0) vibrational bands recorded using the b³0⁺ _u ← X¹0_g ⁺ and B³1?←?X¹0⁺ transitions in Cd₂ and CdAr complexes, respectively, are presented and analysed. Specifically, CdAr and Cd₂ complexes are simultaneously propagating in a supersonic beam. Transitions in these complexes can be used to provide the conditions for selective detection of one of the complexes in the expansion. Extended analysis of the B³1- and b³0⁺ _u -state vibrational progressions provided improved values for ω′ _e x′ _e and ω′ _e vibrational characteristics, as well as D′ _e well depths and R _e ′ bond lengths of the B³1- and b³0⁺ _u-state potentials. Several of the CdAr bands were recorded with partly resolved rotational structure. The new characterisation of the B³1 state, along with results of the rotational and isotopic analyses of the band profiles, agrees with the most recent results of ab initio calculations, while results obtained for the b³0⁺ _u state call for improvement in the ab initio calculations for Cd₂.     

多模叠加态|Ψe4,Ⅲ〉q中广义电场分量的N次方H压缩

利用多模压缩态理论,详细研究了由多模偶相干态和多模虚偶相干态的线性叠加所组成的一种新型的四态叠加多模叠加态光场|Ψ_e⁴,Ⅲ〉_q中广义电场分量的等幂次N次方H压缩特性结果表明:1)在腔模总数q与压缩次数N的乘积q·N=4m(m=1,2,3,…)的条件下,态|Ψ_e⁴,Ⅲ〉_q的广义电场分量可恒处于等幂次NH最小测不准态2)在q·N=4m’+2(m’=0,1,2,…)的条件下,当态间的初始相位差(θ₁-θ₂)、各模的初始相位和 φ_j,以及各模平均光子数之总和 R_j²等分别满足一定的取值条件时,态|Ψ_e⁴,Ⅲ〉_q的广义电场分量总可呈现出周期性变化的偶数次的等幂次N次方H压缩效应.     

增加光子对和减少光子对相干态的统计性质

引入增加光子对相干态|ζ,q;m >_a=a^+m|ζ,q >和减少光子对相干态|ζ,q;-m >_b=b^m|ζ,q >,研究了这些态所描写的光场的统计性质。结果显示当在对相干态的a模增加光子时,两模的平均光子数均增加,亚泊松分布性质增强;当在对相干态的b模取走光子时,b模的平均光子数减少,而a模的平均光子数却增加;b模的亚泊松分布性质减弱,而a模的亚泊松分布性质却增强。我们还计算了场模间的相关度和场模的压缩。     

An ab initio study of the Ne-CO complex

A new ab initio potential energy surface of the Ne-CO complex is developed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations [CCSD(T)].The potential has a minimum value of 49.396 cm 1 at R e = 6.40a 0 with approximately T-shaped geometry(θ e = 82.5).Bound state energies are calculated up to J = 12.The theoretically predicted transition frequencies and spectroscopic constants are in good agreement with the available experimental results.     

Multipole mixing ratios of electromagnetic transitions in Gd

Using γ-γ(θ), γ(θ) (nuclear orientation) and e_k-γ(θ) directional correlation techniques, we have determined the multipole character of some transitions connecting the quadrupole and octupole quasi-vibrational bands to the ground state quasi-rotational band in ¹⁵²Gd following the decay of ¹⁵²Tb. For the γ-γ directional correlation measurements a high-energy resolution system employing a Ge(Li) and a NaI(Tl) detector was used while for the e_k-γ correlation we used a NaI(Tl) and magnetic lens spectrometer system. The nuclear orientation measurements were carried out at low temperatures obtained with a ³He-⁴He dilution refrigerator. The results show that the 2⁺ → 2⁺ transition between the β-vibrational and the ground state bands contains ≈ 10% Ml admixture, δ = − 3.05 ± 0.14, and a large E0 contribution while the similar transition from the γ-vibrational band has δ = 4.3 ± 0.7. These results are compared with Kumar's predictions for similar transitions in ¹⁵²Sm. Three other mixing ratios were also determined.     

Symmetry and boundness of four-particle coulomb systems

The problem of boundness of a ⁺ b ⁺ c ⁻ d ⁻ four-particle Coulomb systems (quadrions) is studied versus the masses of the particles involved. Inequalities that make it possible to deduce that, if some reference quadrions form a bound state, the same is true for a large number of quadrions formed by particles having various masses were derived. A compendium of calculations for energies of reference systems that possess various symmetries [positronium molecules (e ⁺ e ⁺ e ⁻ e ⁻) and quadrions of the a ⁺ b ⁺ b ⁻ b ⁻, a ⁺ b ⁺ a ⁻ b ⁻, and a ⁺ a ⁺ b ⁻ c ⁻ types] is given, and groups of bound asymmetric quadrions corresponding to them are determined. An inequality for kinetic energies of particles that makes it possible to find out, by using asymmetric reference systems, whether specific quadrions are bound is obtained. It is shown that the boundness of many quadrions is ensured by the boundness of respective three-particle systems. The entire body of the present results permits proving that, of the total number of 406 quadrions containing electrons, muons, pions, kaons, protons, deuterons, and tritons and their antiparticles, 227 quadrions are bound.     

四态叠加多模叠加态光场|Ψe(4),Ⅲ〉q的等阶N次方Y压缩

根据量子力学的线性叠加原理,构造了由多模偶相干态与多模虚偶相干态组成的第Ⅲ种四态叠加多模叠加态光场态|Ψ_e⁽⁴⁾,Ⅲ〉_q的等阶N次方Y压缩特性.结果发现:1) 当压缩阶数N=4m,(m=1,2,3,…)时,态|Ψ_e⁽⁴⁾,Ⅲ〉_q恒处于等阶数N-Y最小测不准态;2) 当压缩阶数N=4m′+2,(m′=0,1,2,…)时,在(θ₁-θ₂),q,R_j,r₁,r₂等取不同的组合定值下,态|Ψ_e⁽⁴⁾,Ⅲ〉_q可分别呈现出等阶N次方Y压缩效应与"半相干态"效应;3) 当压缩阶数N为奇数时,在(θ₁-θ₂),q,R_j,r₁,r₂等取不同的组合定值下,态|Ψ_e⁽⁴⁾,Ⅲ〉_q可呈现出等阶N次方Y压缩效应.     

Level structure of 123Cs observed from 123Ba decay and described using the IBFM and CQPC models

The decay of ¹²³Ba to ¹²³Cs has been studied with mass-separated sources. Singles spectra of γ-rays, X-rays and conversion electrons as well as γ - γ - t, γ - e ⁻ - t, and X - e ⁻ - t coincidences were recorded. A level scheme of ¹²³Cs has been constructed including 26 new excited states and 82 transitions. The existence of a I ^π = 11/2⁻, T _1/2 = 1.7 s isomer, bandhead of the h _11/2 band, is confirmed. Its excitation energy equals 156.3 keV. A new T _1/2 = 114 ns isomer has been established at 232 keV using the in-beam recoil catcher technique. It is assigned to the I ^π = 9/2⁺ bandhead of the gpg _9/2 band. Collective bands based on the 1/2⁺ ground state and first 3/2⁺ excited state are proposed. The level structure is described in the frame of the interacting boson-fermion and core-quasiparticle coupling models.     

Positron scattering from hydrocarbons

The total cross sections for positron impact on hydrocarbons have been calculated using the additivity rule in which the total cross section for a molecule is the sum of the total cross section for the constituent atoms. The energy range considered is from a few eV to several thousand eV. The total cross sections for positron impact on an atom are calculated by employing a complex spherical potential which comprises of a static, polarization and an absorption potential. We have good agreement with the experimental results for hydrocarbons for positron energy ⩾100 eV. Our results also agree with the available calculations for CH₄ and C₂H₂ which employed full molecular wavefunctions beyond 100 eV. Our absorption cross sections also agree with molecular wave-function calculations for C₂H₂ and CH₄ beyond 100 eV. We have shown the Bethe plots fore ⁺−C ande ⁺−H scattering systems and Bethe parameters have been extracted. We have fitted the cross section for positron impact on hydrocarbons in the formσ _t(C _n H _m )=naE ⁻ b+mcE ⁻ d in the energy range 300–5000 eV wherea=195.0543,b=0.7986,c=371.1757 andd=1.1379 withE in eV andσ _t in 10⁻¹⁶ cm².     

Fourier Transform Infrared Emission Spectroscopy of thebΠ–aΣSystem of BN

The emission spectrum of BN has been investigated in the 1800–9000 cm⁻¹region using a Fourier transform spectrometer. BN was formed in a microwave discharge of He with a trace of BCl₃and N₂. The bands observed in the 3000–7800 cm⁻¹interval have been assigned as theb¹Π–a¹Σ⁺transition, with the 0–0 band at 3513.99040(43) cm⁻¹. This transition is analogous to theA¹Π_u–X¹Σ⁺_g(Phillips) system of the isoelectronic C₂molecule. The rotational analysis of the 0–0, 1–1, 1–0, 2–1, 3–2, 2–0, 3–1, 4–2, and 4–1 bands has been obtained and the molecular constants for theb¹Π anda¹Σ⁺states have been determined. A local perturbation has been observed in thev= 1 vibrational level of theb¹Π state nearJ= 18 caused by the interaction with thev= 3 vibrational level of thea¹Σ⁺state. The principal equilibrium constants for thea¹Σ⁺state are: ω_e= 1705.4032(11) cm⁻¹, ω_ex_e= 10.55338(52) cm⁻¹,B_e= 1.683771(10), α_e= 0.013857(16) cm⁻¹, andr_e= 1.2745081(37) Å. Although theb¹Π–a¹Σ⁺transition has recently been seen in emission from boron nitride trapped in solid neon matrices [J. Chem. Phys.104,3143–3146 (1996)], our work represents the first observation of this transition of BN in the gas phase.     

态|Ψ(3)〉q中广义电场分量的不等幂次Nj次方Y压缩

利用多模压缩态理论,研究了由多模复共轭虚相干态|{iZ_j^*}〉q、多模复共轭虚相干态的相反态|{-iZ_j^*}〉q和多模复共轭相干态|{Z_j^*}〉q的线性叠加所组成的新型三态叠加多模叠加态光场|Ψ⁽³⁾〉_q中广义电场分量的偶数次不等幂次Nj次方Y压缩特性.结果发现:在各模的压缩次数N_j=2pj且pj=2m′j+1(m′j=0,1,2,3,…,…)和Nj′=2pj′且pj′=2m′j′+1(m′j′=0,1,2,3,…,…)的条件下,当各模的初始相位φ_j与φ_j′、态间的初始相位差(θ₁-θ₃)与(θ₂-θ₃),以及各单模相干态光场总的平均光子数之和qj=1R2j等分别满足一定的取值条件时,态|Ψ⁽³⁾〉_q的广义电场分量(即第二正交相位分量)总可呈现出周期性变化的、偶数次的广义非线性不等幂次N_j次方Y压缩效应.     

Effect of anomalous tbW vertex on decay-lepton distributions in e + e − → tt and CP-violating asymmetries

We obtain analytic expressions for the energy and polar-angle double differential distributions of a secondary lepton l ⁺ (l ⁻) arising from the decay of t(t) in e ⁺ e ⁻ → tt with an anomalous tbW decay vertex. We also obtain analytic expressions for the various differential cross-sections with the lepton energy integrated over. In this case, we find that the angular distributions of the secondary lepton do not depend on the anomalous coupling in the decay, regardless of possible anomalous couplings occurring in the production amplitude for e ⁺ e ⁻ → tt. Our study includes the effect of longitudinal e ⁻ and e ⁺ beam polarization. We also study the lepton energy and beam polarization dependence of certain CP-violating lepton angular asymmetries arising from an anomalous tbW decay vertex and compare them with the asymmetries arising due to CP-violation in the production process due to the top electric or weak dipole moment.     

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.     

增加光子奇偶q相干态的高阶压缩效应

通过数值计算研究了增加光子奇q相干态a_q^+m|α>_q^o和增加光子偶q相干态a_q^+m|α>_q^e的高阶压缩效应.结果表明:当q较小时,态a_q^+m|α>_q^o和a_q^+m|α>_q^e都能呈现出强烈的奇次方阶压缩效应,但无偶次方阶压缩效应,而且奇次方阶压缩随m的增大而增强.当m=0时a_q^+m|α>_q^o和a_q^+m|α>_q^e为光场振幅偶次幂的最小测不准态,但当m≠0时它们不是光场振幅偶次幂的最小测不准态.     

MgH分子X2Σ+，A2Π和B2Σ+电子态的势能函数

利用QCISD(T),SAC-CI方法和cc-pVQZ,aug-cc-pVTZ,6-311++G及6-311++G(3df,2pd)基组,对MgH分子的基态X²Σ⁺,第一简并激发态A²Π和第二激发态B²Σ⁺的结构进行优化计算.通过对4个基组计算结果进行比较,得出6-311++G(3df,2pd)基组为最优基组.使用 关键词： 分子结构与势能函数 激发态 Murrell-Sorbie函数 C₆函数')" href="#">Murrell-Sorbie+C₆函数     

第Ⅶ类两态叠加多模叠加态光场的偶数阶等阶N次方Y压缩

本文构造了由多模相干态|{Z_j}>_q与多模虚相干态的相反态|{-iZ_j}>_q这两者的线性叠加所组成的第Ⅶ类两态叠加多模叠加态光场|ψ₇⁽²⁾>_q.利用多模压缩态理论,研究了态|ψ₇⁽²⁾>_q的偶数阶等阶N次方Y压缩特性.结果发现:在压缩阶数N=2p、并且P=2m+1(m=0,1,2,3,…,…)的条件下,如果各模的初始相位φj(j=1,2,3,…,q)、态间的初始相位差与各单模相干态光场的平均光子数之和 等分别满足一定的取值条件,则在这种情况下态|ψ₇⁽²⁾>_q可呈现出周期性变化的偶数阶等阶N次方Y压缩效应.