Vibration-rotation and deperturbation analysis of A2Π-X2Σ+ and B2Σ+-X2Σ+ systems of the CaI molecule

Doppler-limited laser excitation spectroscopy employing narrow-band fluorescence detection was used to obtain a rotational and vibrational analysis in the (0, 0) and (1, 1) bands of the A²Π-X²Σ⁺ system and the (4, 2) (3, 1), (0, 0), (0, 1), (1, 2), (2, 3), and (3, 4) bands of the B²Σ⁺-X²Σ⁺ system of CaI. The A and B states are deperturbed to obtain spectroscopic constants and Franck-Condon factors. Deperturbation was necessary because of the small separation of the A and B states relative to the A ～ B interaction strength and the A²Π spin-orbit splitting. The main deperturbed constants (in cm^?1) are

     

2.

Laser spectroscopy of CaBr: A²Π-X²Σ⁺ and B²Σ⁺-X²Σ⁺ systems     

P.F. Bernath  R.W. Field  B. Pinchemel  Y. Lefebvre  J. Schamps 《Journal of Molecular Spectroscopy》1981,88(1):175-193

Laser excitation spectra have been recorded for Ca⁷⁹Br and Ca⁸¹Br in the spectral region 600–630 nm. The use of a 1-m monochromator as a narrow band pass filter (1–2 cm^?1) has allowed rotational analysis of the 0-0, 1-1, and 2-2 bands of the B²Σ⁺ - X²Σ⁺ transition and the 0-0 and 1-1 bands of the A²Π - X²Σ⁺ transition. A few additional lines of the 0-1, 1-2, 1-0, and 2-1 bands of the B-X system were used to obtain band origins for vibrational analysis. The main constants for Ca⁷⁹Br are (in cm^?1):

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^2\text{Π}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	15 624.67(5)	15 700.52(12)
$\text{ω}{}_{\mathrm{e}}$	238.7496(33)	241.19(7)	242.63(17)
$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	0.62789(64)	0.53(5) (Pekeris)	1.17(12) (Pekeris)
$\text{B}{}_{\mathrm{e}}$	0.0693254(84)	0.070460(14)	0.071572(22)
$\text{α}{}_{\mathrm{e}}\text{× 10}{}^4$	2.640(35)	2.15(10)	3.95(2)
$\text{A}{}_{\mathrm{e}}$	—	45.8968(52)	—
$\text{R}{}_{\mathrm{e}}\text{(}\text{A}\text{?}\text{)}$	2.8286(2)	2.8057(3)	2.7839(4)

     

3.

Effect of unitarization on the amplitudes for the decays K₁⁰ → π⁺π^? and K⁺ → π⁺π⁺π^?     

E. P. Shabalin 《Physics of Atomic Nuclei》2010,73(11):1908-1915

The unitarization of the amplitude for the decay process K ₁⁰ → π⁺π⁻ and allowance for the rescattering of final-state pions in the decay process K ⁺ → π⁺π⁺π⁻ make it possible to evaluate, by using the parameters extracted from data on K → 2π decays, the K ⁺ → π⁺π⁺π⁻ decay width. The result agrees with the experimental width value at a level of a few percent. Allowance for corrections for higher order terms of the momentum expansion of the amplitude for the decay process K ⁺ → π⁺π⁺π⁻ leads to the slope-parameter value of g ₊₊₋^th = 0.2182, which agrees with its experimental counterpart, g ₊₊₋^exp = 0.2154 ± 0.0035.     

4.

F₂ Σ⁺ -X ²Σ ⁺Band System of Cobalt Carbide     

郭静茹  张朝霞  王婷婷  陈从香  陈旸 《化学物理学报》2008,21(6):505-509

用脉冲直流放电产生Xe原子亚稳态5p56s[3/2]2和5p56s′[1/2]0.在单光子28000－42000cm-1能量范围内,结合飞行时间质谱技术获得Xe原子共振增强激发光谱.光谱分析表明,所有谱线来源于Xe原子5p56s[3/2]2和5p56s′[1/2]0两个亚稳态吸收单个光子向偶宇称np′、nf′自电离Rydberg态序列的跃迁.实验观测到许多新的自电离能级,并获得更精确和系统的能级位置和量子亏损值数据.     

5.

On the spin correlations of muons generated in the annihilation process e ⁺ e ^? → μ⁺μ^?     

V. L. Lyuboshitz  V. V. Lyuboshitz 《Physics of Atomic Nuclei》2009,72(2):311-318

Using the technique of helicity amplitudes, the electromagnetic process e ⁺ e ⁻ → μ⁺μ⁻ is theoretically investigated in the one-photon approximation. The structure of the triplet states of the final (μ⁺μ⁻) system is analyzed. It is shown that in the case of unpolarized electron and positron the finalmuons are also unpolarized, but their spins are strongly correlated. Explicit expressions for the components of the correlation tensor of the final (μ⁺μ⁻) system are derived. The formula for the angular correlation at the decays of final muons μ⁺ and μ⁻, produced in the process e ⁺ e ⁻ → μ⁺μ⁻, is obtained. It is demonstrated that spin correlations of muons in the process of electron-positron pair annihilation have the purely quantum character, since one of the incoherence inequalities for the correlation-tensor components is always violated. The additional contribution of the weak interaction of lepton neutral currents through the virtual Z ⁰ boson is considered; it is established that, taking into account the weak interaction, the qualitative character of the muon spin correlations does not change. The text was submitted by the authors in English.     

6.

ρ⁰ production the reaction ξξ→3π⁺3π^?ξξ→ρ⁰ρ⁰(1700)     

H. -J. Behrend  L. Criegee  J. H. Field  G. Franke  H. Jung  J. Meyer  O. Podobrin  V. Schr?der  G. G. Winter  P. J. Bussey  et al. 《Zeitschrift fur Physik C Particles and Fields》1991,49(1):43-48

We have studied the ⁰ production rate in the reaction 3⁺3^– in the energy range 1.6W 7.5 GeV with the CELLO detector at PETRA. Our analysis points to a substantial yield of ^00+– events in particular atW >4.0 GeV. We give cross sections for the ⁰2⁺2^– and ^00+– final states and calculate upper limits for the reaction ⁰⁰ (1700) ^00+–.Now at CERN     

7.

²⁰ Ne(³⁴ Ne)原子与¹⁸ Na₂(²³ Na₂,³⁷ Na₂)分子低温下冷碰撞的同位素效应研究          下载免费PDF全文

臧华平  李文峰  令狐荣锋  程新路  杨向东 《物理学报》2011,60(5):50303-050303

本文用多体刚性椭球模型计算了相对入射能量为190 meV时,氖的同位素原子²⁰Ne,³⁴Ne与钠的同位素分子¹⁸Na₂,²³Na₂,³⁷Na₂ 替代碰撞体系的态态转动激发积分散射截面和总转动激发积分散射截面,在此基础上计算并分析了相互作用势的不同区域对²⁰Ne-¹⁸Na_{2关键词： 多体刚性椭球模型 转动激发积分散射截面 钠同位素分子 椭球等势面}     

8.

射流冷却AlO自由基B²Σ⁺—X²Σ⁺光谱研究          下载免费PDF全文

金瑾  陈旸  裴林森  胡长进  马兴孝  陈从香 《物理学报》2000,49(9):1689-1691

利用铝电极放电产生的Al原子与O₂反应生成AlO自由基,在超声射流冷却下在43 0—480nm波长范围观测到AlO自由基B—X跃迁的激光诱导荧光激发谱.光谱振动结构分析表明 所有的谱带属于V′-V″=1,2,3跃迁,并获得基态和激发态的振动频率与非谐性常数.另外还 对其中(1,4)谱带的转动结构进行标识,并得到相应的转动常数和离心畸变系数.对从基态 振动能级V″=5向上跃迁的谱带强度增强进行了讨论. 关键词： 光谱 AlO     

9.

Lifetime vibrational interference during the NO 1s^-1π^* resonant excitation studied by the NO⁺(A ¹Π → X ¹Σ⁺) fluorescence     

A. Ehresmann  W. Kielich  L. Werner  Ph. V. Demekhin  D. V. Omel''yanenko  V. L. Sukhorukov  K.-H. Schartner  H. Schmoranzer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(2):235-246

Dispersed fluorescence from fragments formed after the de-excitation of the 1s^-1π^* resonances of N^*O and NO^* has been measured in the spectral range of 118–142 nm. This range is dominated by lines of atomic nitrogen and oxygen fragments and by the bands in the NO⁺ ion which result from the participator Auger decay of the 1s^-1π^* resonances. Ab-initio calculations of the transition probabilities between vibrational levels during the reaction NO N^*O ⇒ NO were used to explain the observed intensity dependence for the fluorescence bands on the exciting-photon energy across the resonances and on both v^′ and v^′′ vibrational quantum numbers. The multiplet structure of the 1s^-1π^* resonance and lifetime vibrational interference explain the observed exciting-photon energy dependence of the fluorescence intensity. A strong spin-orbit coupling between singlet and triplet states of NO⁺ is proposed to reduce additional cascade population of the state via radiative transitions from the and states and to explain remaining differences between measured and calculated integral fluorescence intensities.     

10.

e⁺e^－→π⁺π^－π⁺π^－形状因子拟合     

翁瑶  胡海明  王骏 《中国物理 C》2007,31(5):419-422

基于BABAR实验组对e⁺e^－→π⁺π^－π⁺π^－的反应截面的测量结果, 用VMD模型给出的理论截面拟合实验数据, 首次从单一反应道得到π⁺π^－π⁺π^－末态形状因子的所有参数值.     

11.

Study of hot bands in the B²Σ⁺_u-X²Σ⁺_g system of C^-₂ anion          下载免费PDF全文

喻姗姗  杨晓华  李本霞  Kaniki Kakule  吴升海  郭迎春  刘煜炎  陈扬骎 《中国物理》2003,12(7):745-749

Optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy was employed to observe the visible absorption spectra of the B^2Σ^+_u-X^2Σ^+_g electronic transition of C^-_2. Four hot bands (0,1), (1,2), (2,3) and (3,4) have been observed and the band (3,4) is measured directly for the first time, so far as we know, by absorption. A rotational analysis was carried out to obtain molecular constants. With the Franck－Condon principle and the vibrational Boltzmann distribution, we have estimated the vibrational temperature of C^-_2 to be about 3000K.     

12.

N₂O⁺离子A²Σ⁺电子态的光解动力学研究          下载免费PDF全文

徐海峰  李奇峰  周晓国  戴静华  刘世林  马兴孝 《物理学报》2004,53(6):1759-1765

用一束波长为360.55nm的激光，通过N2O分子的（3+1）共振多光子电离（REMPI）过程制备纯净且布居完全处于X2Π(000)态的母体离子N2O+，然后用另一束波长在275—328nm范围内的可调谐激光将制备的N2O+离子激发至预解离电子态A2Σ+.实验发现，由于解离碎片NO+所具有的一定的反冲速度，其TOF质谱峰明显比N2O+母体宽.通过分析NO+碎片TOF质谱峰形状，得到了解离产物的总平均平动能〈ET〉；通过考察〈ET〉随光解能量的变化，发现光解能量在32000cm-1附近约250cm-1的变化 关键词： N2O+离子A2Σ+态 TOF质谱峰 预解离机理     

13.

OCS⁺分子经由B²∑⁺←X²∏跃迁的光解离谱     

周丹娜  张立敏  陈琳  吴丹 《化学物理学报》2013,26(3):265-269

制备出确定旋轨态的OCS⁺(X²∏)离子,在260～325 nm波长范围内研究了OCS^{+经由B2∑+←X2∏_3/2(000)和B2∑+←X2∏_1/2(000,001)跃迁的分质量光解离谱．由光解离谱得到OCS+(B2∑+)电子态的光谱常数υ1(CS stretch)=828.9(810.4) cm-1,υ2(bend)=491.3 cm-1和υ3(CO stretch)=1887.2 cm-1．在B2∑+←X2∏跃迁谱中只能观察到B2∑+(010)←X2∏_1/2(000)跃迁的谱峰, 而观察不到B2∑+←X2∏_3/2(000)跃迁的谱峰． 用X2∏电子态的(000)2∏_1/2和(010)2∑+_1/2电子振动能级之间的K耦合解释了这种B2∑+的υ2弯曲振动模的激发对X2∏电子态的旋轨分裂分量(Ω=1/2,3/2)的相关性}     

14.

a₂(1320)→π⁺π⁺π^－过程的三体振幅分析     

朱界杰  阮图南 《中国物理 C》1998,22(4):326-332

对a₂(1320)→π⁺π⁺π^－过程的衰变振幅进行张量分析,展示了如何得到三体衰变振幅.     

15.

Reaction e ⁺ e ^? → π ⁺ π ^? π ⁺ π ^? at energies of √ s ≤ 1 GeV     

N. N. Achasov  A. A. Kozhevnikov 《JETP Letters》2008,88(1):1-4

The e ⁺ e ⁻ → π ⁺ π ⁻ π ⁺ π ⁻ cross section is calculated for energies of 0.65 ≤ √s ≤ 1 GeV in the framework of the generalized hidden local symmetry model. The calculations are compared with the data of CMD-2 and BaBaR. It is shown that the inclusion of heavy isovector resonances ρ(1450) and ρ(1700) is necessary for reconciling calculations with the data. It is found that, at √s ≈ 1 GeV, the contributions of the above resonances are much larger, by a factor of 30, than the ρ(770) one, and amount to a considerable fraction ∼0.3–0.6 of the latter at √s ∼ m _ρ. The text was submitted by the authors in English.     

16.

B ^?→ K ₁^*? (1270)(→ ρ ⁰ K ^?) ? ⁺ ? ^? in LEET     

S. Rai Choudhury  A. S. Cornell  Naveen Gaur 《The European Physical Journal C - Particles and Fields》2008,58(2):251-259

Flavor changing neutral current (FCNC) decays of the B-meson are a very useful tool for studying possible physics scenarios beyond the standard model (SM), where of the many FCNC modes radiative, purely leptonic and semi-leptonic decays of the B-meson are relatively clean tests. Within this context, the BELLE collaboration has measured the process B→K ^* γ and also searched for the B→K ₁(1270)γ process. Theoretical analyses of these processes are yielding similar values of the relevant form factors. In this work we have used this upper bound in studying the angular correlations for the related semi-leptonic decay mode B ⁻→K ₁⁻(1270)(→ρ ⁰ K ⁻)ℓ ⁺ ℓ ⁻, where we have used the form factors that have already been estimated for the B→K ₁(1270)γ mode. Note that the additional form factors that are required were calculated using large energy effective theory (LEET).     

17.

基于从头算势能面对S^-(²P)+H₂(¹Σ⁺_g)→SH^-(¹Σ)+H(²S)反应的量子含时波包计算     

马宏宇  张成园  宋玉志  马凤才  李永庆 《化学物理学报》2022,(2):338-344

本文基于离子分子SH₂^-基态势能面,应用含时波包方法研究了反应S^-(²P)+H₂(¹Σ⁺_g)→SH^-(¹Σ)+H(²S)的动力学行为. 给出了反应几率和积分截面随碰撞能的变化关系,结果表明,在讨论的所有碰撞能量范围内二者均存在显著的振荡结构. 当初始转动量子数j=0,2,4,6,8,10和振动量子数v=0,1,2,3,4时,从总反应几率数值计算中可以看出,双原子H₂的振动激发和转动激发显著提高了反应活性. 同时积分散射截面的理论值与前人的实验值相符合.     

18.

Theoretical study of the A ³ 0 ⁺ ← X ¹ 0 ⁺ and B ³ 1 ← X ¹ 0 ⁺ transitions in the Cd-rare gas van der Waals molecules     

E. Czuchaj  M. Kro&#;nicki  J. Czub 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(3):345-353

Excitation spectra arising from A ³ 0 ⁺ ← X ¹ 0 ⁺ and B ³ 1 ← X ¹ 0 ⁺ electronic transitions in the Cd-rare gas (RG) van der Waals molecules are calculated using newly obtained theoretical potential curves for these species. In the molecular structure calculations, Cd²⁰⁺ and RG⁸⁺ cores are simulated by energy-consistent pseudopotentials which also account for scalar-relativistic effects and spin-orbit (SO) interaction within the valence shell. Potential energies in the Λ S coupling scheme have been obtained by means of ab initio complete-active-space multiconfiguration self consistent-field (CASSCF)/complete-active-space multireference second-order perturbation theory (CASPT2) calculations with a total 28 correlated electrons, while the SO matrix has been computed in a reduced CI space restricted to the CASSCF level. The final Ω potential curves are obtained by diagonalization of the modified SO matrix (its diagonal elements before diagonalization substituted for the corresponding CASPT2 eigen-energies). The spectroscopic parameters for the ground and several excited states of the Cd-RG complexes deduced from the calculated potential curves are in quite reasonable agreement with available experimental data. In addition, the radial Schr?dinger equation for nuclear motion was solved numerically with the calculated potentials to evaluate the corresponding vibrational levels and radial wavefunctions. The latter have been used in the calculation of the appropriate Franck-Condon factors to yield information on relative intensities of the vibrational bands of the Cd-RG complexes. The theoretical vibrational progressions are discussed in the context of experimental spectra. Received 10 August 2000 and Received in final form 7 November 2000     

19.

CP -violation effects in the decays B ^? → D ^* K ^*? and method for determining the weak phase γ     

V. A. Kovalchuk 《Physics of Atomic Nuclei》2007,70(4):722-731

A method for determining the angle γ and the ratio of the amplitudes A _λ(B ⁻ → K ^*−) and A _λ)B ⁻ → D ^*0 K ^*−), r _Bλ, for all three vector-meson polarization states by using the decays B ^∓ → D ^* K ^*∓ is proposed. This method relies on the interference between the decays B ⁻ → D ^*0 K ^*− and B ⁻ → K ^*−, which arises if D ^*0 and decay to D ⁰/ π ⁰ and D ⁰/ γ, whereupon D ⁰ and mesons decay to common final hadron states. The doubly Cabibbo-suppressed modes of D ⁰-meson decay are chosen here to specify such final states. Original Russian Text ? V.A. Kovalchuk, 2007, published in Yadernaya Fizika, 2007, Vol. 70, No. 4, pp. 754–763.     

20.

Perturbations in the A¹Π-X¹Σ⁺ system of the BeO molecule     

H. Lavendy  B. Pouilly  J.M. Robbe 《Journal of Molecular Spectroscopy》1984,103(2):379-407

All perturbations observed by Lagerqvist (Thesis, University of Stockholm, 1948) in the A¹Π-X¹Σ⁺ transition have been assigned to a³Π₂, a³Π₁, and X¹Σ⁺ states. Vibrational and rotational constants of the a³Π state as well as electronic parameters for A ～ X, A ～ a, and a ～ X interactions have been determined.

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^2\text{Π}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	15 958.41 (10)	16 383.137 (6)
$\text{ω}{}_{\mathrm{e}}$	285.732 (9)	288.56 (20)	285.747 (9)
$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	0.840 (4)	—	0.954 (4)
$\text{B}{}_{\mathrm{e}}$	0.094466141 (30)	0.0957343 (20)	0.0965151 (20)
$\text{α}{}_{\mathrm{e}}$	0.000403551 (40)	0.0004327 (20)	0.0004483 (15)
$\text{γ}{}_{\mathrm{e}}$ (spin-rot.)	0.00301484 (50)	—	0.068767 (79)
$\text{P}{}_{\mathrm{e}}$	—	?0.066834 (64)	—
$\text{A}{}_{\mathrm{e}}$	—	59.175 (1)	—

     

	Reciprocal centimeters
	Te	ωe	ωexe	Be	αe	re (Å)
a3Π	8574	1132	8.4	1.3675	?0.0168	1.4623

Laser spectroscopy of CaBr: A2Π-X2Σ+ and B2Σ+-X2Σ+ systems

Laser excitation spectra have been recorded for Ca⁷⁹Br and Ca⁸¹Br in the spectral region 600–630 nm. The use of a 1-m monochromator as a narrow band pass filter (1–2 cm^?1) has allowed rotational analysis of the 0-0, 1-1, and 2-2 bands of the B²Σ⁺ - X²Σ⁺ transition and the 0-0 and 1-1 bands of the A²Π - X²Σ⁺ transition. A few additional lines of the 0-1, 1-2, 1-0, and 2-1 bands of the B-X system were used to obtain band origins for vibrational analysis. The main constants for Ca⁷⁹Br are (in cm^?1):

Effect of unitarization on the amplitudes for the decays K10 → π+π? and K+ → π+π+π?

The unitarization of the amplitude for the decay process K ₁⁰ → π⁺π⁻ and allowance for the rescattering of final-state pions in the decay process K ⁺ → π⁺π⁺π⁻ make it possible to evaluate, by using the parameters extracted from data on K → 2π decays, the K ⁺ → π⁺π⁺π⁻ decay width. The result agrees with the experimental width value at a level of a few percent. Allowance for corrections for higher order terms of the momentum expansion of the amplitude for the decay process K ⁺ → π⁺π⁺π⁻ leads to the slope-parameter value of g ₊₊₋^th = 0.2182, which agrees with its experimental counterpart, g ₊₊₋^exp = 0.2154 ± 0.0035.     

F2 Σ+ -X 2Σ +Band System of Cobalt Carbide

用脉冲直流放电产生Xe原子亚稳态5p56s[3/2]2和5p56s′[1/2]0.在单光子28000－42000cm-1能量范围内,结合飞行时间质谱技术获得Xe原子共振增强激发光谱.光谱分析表明,所有谱线来源于Xe原子5p56s[3/2]2和5p56s′[1/2]0两个亚稳态吸收单个光子向偶宇称np′、nf′自电离Rydberg态序列的跃迁.实验观测到许多新的自电离能级,并获得更精确和系统的能级位置和量子亏损值数据.     

On the spin correlations of muons generated in the annihilation process e + e ? → μ+μ?

Using the technique of helicity amplitudes, the electromagnetic process e ⁺ e ⁻ → μ⁺μ⁻ is theoretically investigated in the one-photon approximation. The structure of the triplet states of the final (μ⁺μ⁻) system is analyzed. It is shown that in the case of unpolarized electron and positron the finalmuons are also unpolarized, but their spins are strongly correlated. Explicit expressions for the components of the correlation tensor of the final (μ⁺μ⁻) system are derived. The formula for the angular correlation at the decays of final muons μ⁺ and μ⁻, produced in the process e ⁺ e ⁻ → μ⁺μ⁻, is obtained. It is demonstrated that spin correlations of muons in the process of electron-positron pair annihilation have the purely quantum character, since one of the incoherence inequalities for the correlation-tensor components is always violated. The additional contribution of the weak interaction of lepton neutral currents through the virtual Z ⁰ boson is considered; it is established that, taking into account the weak interaction, the qualitative character of the muon spin correlations does not change. The text was submitted by the authors in English.     

ρ0 production the reaction ξξ→3π+3π?ξξ→ρ0ρ0(1700)

We have studied the ⁰ production rate in the reaction 3⁺3^– in the energy range 1.6W 7.5 GeV with the CELLO detector at PETRA. Our analysis points to a substantial yield of ^00+– events in particular atW >4.0 GeV. We give cross sections for the ⁰2⁺2^– and ^00+– final states and calculate upper limits for the reaction ⁰⁰ (1700) ^00+–.Now at CERN     

20 Ne(34 Ne)原子与18 Na2(23 Na2,37 Na2)分子低温下冷碰撞的同位素效应研究

本文用多体刚性椭球模型计算了相对入射能量为190 meV时,氖的同位素原子²⁰Ne,³⁴Ne与钠的同位素分子¹⁸Na₂,²³Na₂,³⁷Na₂ 替代碰撞体系的态态转动激发积分散射截面和总转动激发积分散射截面,在此基础上计算并分析了相互作用势的不同区域对²⁰Ne-¹⁸Na_{2关键词： 多体刚性椭球模型 转动激发积分散射截面 钠同位素分子 椭球等势面}     

射流冷却AlO自由基B2Σ+—X2Σ+光谱研究

利用铝电极放电产生的Al原子与O₂反应生成AlO自由基,在超声射流冷却下在43 0—480nm波长范围观测到AlO自由基B—X跃迁的激光诱导荧光激发谱.光谱振动结构分析表明 所有的谱带属于V′-V″=1,2,3跃迁,并获得基态和激发态的振动频率与非谐性常数.另外还 对其中(1,4)谱带的转动结构进行标识,并得到相应的转动常数和离心畸变系数.对从基态 振动能级V″=5向上跃迁的谱带强度增强进行了讨论. 关键词： 光谱 AlO     

Lifetime vibrational interference during the NO 1s-1π* resonant excitation studied by the NO+(A 1Π → X 1Σ+) fluorescence

Dispersed fluorescence from fragments formed after the de-excitation of the 1s^-1π^* resonances of N^*O and NO^* has been measured in the spectral range of 118–142 nm. This range is dominated by lines of atomic nitrogen and oxygen fragments and by the bands in the NO⁺ ion which result from the participator Auger decay of the 1s^-1π^* resonances. Ab-initio calculations of the transition probabilities between vibrational levels during the reaction NO N^*O ⇒ NO were used to explain the observed intensity dependence for the fluorescence bands on the exciting-photon energy across the resonances and on both v^′ and v^′′ vibrational quantum numbers. The multiplet structure of the 1s^-1π^* resonance and lifetime vibrational interference explain the observed exciting-photon energy dependence of the fluorescence intensity. A strong spin-orbit coupling between singlet and triplet states of NO⁺ is proposed to reduce additional cascade population of the state via radiative transitions from the and states and to explain remaining differences between measured and calculated integral fluorescence intensities.     

e+e－→π+π－π+π－形状因子拟合

基于BABAR实验组对e⁺e^－→π⁺π^－π⁺π^－的反应截面的测量结果, 用VMD模型给出的理论截面拟合实验数据, 首次从单一反应道得到π⁺π^－π⁺π^－末态形状因子的所有参数值.     

Study of hot bands in the B2Σ+u-X2Σ+g system of C-2 anion

Optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy was employed to observe the visible absorption spectra of the B^2Σ^+_u-X^2Σ^+_g electronic transition of C^-_2. Four hot bands (0,1), (1,2), (2,3) and (3,4) have been observed and the band (3,4) is measured directly for the first time, so far as we know, by absorption. A rotational analysis was carried out to obtain molecular constants. With the Franck－Condon principle and the vibrational Boltzmann distribution, we have estimated the vibrational temperature of C^-_2 to be about 3000K.     

N2O+离子A2Σ+电子态的光解动力学研究

用一束波长为360.55nm的激光，通过N2O分子的（3+1）共振多光子电离（REMPI）过程制备纯净且布居完全处于X2Π(000)态的母体离子N2O+，然后用另一束波长在275—328nm范围内的可调谐激光将制备的N2O+离子激发至预解离电子态A2Σ+.实验发现，由于解离碎片NO+所具有的一定的反冲速度，其TOF质谱峰明显比N2O+母体宽.通过分析NO+碎片TOF质谱峰形状，得到了解离产物的总平均平动能〈ET〉；通过考察〈ET〉随光解能量的变化，发现光解能量在32000cm-1附近约250cm-1的变化 关键词： N2O+离子A2Σ+态 TOF质谱峰 预解离机理     

OCS+分子经由B2∑+←X2∏跃迁的光解离谱

制备出确定旋轨态的OCS⁺(X²∏)离子,在260～325 nm波长范围内研究了OCS^{+经由B2∑+←X2∏_3/2(000)和B2∑+←X2∏_1/2(000,001)跃迁的分质量光解离谱．由光解离谱得到OCS+(B2∑+)电子态的光谱常数υ1(CS stretch)=828.9(810.4) cm-1,υ2(bend)=491.3 cm-1和υ3(CO stretch)=1887.2 cm-1．在B2∑+←X2∏跃迁谱中只能观察到B2∑+(010)←X2∏_1/2(000)跃迁的谱峰, 而观察不到B2∑+←X2∏_3/2(000)跃迁的谱峰． 用X2∏电子态的(000)2∏_1/2和(010)2∑+_1/2电子振动能级之间的K耦合解释了这种B2∑+的υ2弯曲振动模的激发对X2∏电子态的旋轨分裂分量(Ω=1/2,3/2)的相关性}     

a2(1320)→π+π+π－过程的三体振幅分析

对a₂(1320)→π⁺π⁺π^－过程的衰变振幅进行张量分析,展示了如何得到三体衰变振幅.     

Reaction e + e ? → π + π ? π + π ? at energies of √ s ≤ 1 GeV

The e ⁺ e ⁻ → π ⁺ π ⁻ π ⁺ π ⁻ cross section is calculated for energies of 0.65 ≤ √s ≤ 1 GeV in the framework of the generalized hidden local symmetry model. The calculations are compared with the data of CMD-2 and BaBaR. It is shown that the inclusion of heavy isovector resonances ρ(1450) and ρ(1700) is necessary for reconciling calculations with the data. It is found that, at √s ≈ 1 GeV, the contributions of the above resonances are much larger, by a factor of 30, than the ρ(770) one, and amount to a considerable fraction ∼0.3–0.6 of the latter at √s ∼ m _ρ. The text was submitted by the authors in English.     

B ?→ K 1*? (1270)(→ ρ 0 K ?) ? + ? ? in LEET

Flavor changing neutral current (FCNC) decays of the B-meson are a very useful tool for studying possible physics scenarios beyond the standard model (SM), where of the many FCNC modes radiative, purely leptonic and semi-leptonic decays of the B-meson are relatively clean tests. Within this context, the BELLE collaboration has measured the process B→K ^* γ and also searched for the B→K ₁(1270)γ process. Theoretical analyses of these processes are yielding similar values of the relevant form factors. In this work we have used this upper bound in studying the angular correlations for the related semi-leptonic decay mode B ⁻→K ₁⁻(1270)(→ρ ⁰ K ⁻)ℓ ⁺ ℓ ⁻, where we have used the form factors that have already been estimated for the B→K ₁(1270)γ mode. Note that the additional form factors that are required were calculated using large energy effective theory (LEET).     

基于从头算势能面对S-(2P)+H2(1Σ+g)→SH-(1Σ)+H(2S)反应的量子含时波包计算

本文基于离子分子SH₂^-基态势能面,应用含时波包方法研究了反应S^-(²P)+H₂(¹Σ⁺_g)→SH^-(¹Σ)+H(²S)的动力学行为. 给出了反应几率和积分截面随碰撞能的变化关系,结果表明,在讨论的所有碰撞能量范围内二者均存在显著的振荡结构. 当初始转动量子数j=0,2,4,6,8,10和振动量子数v=0,1,2,3,4时,从总反应几率数值计算中可以看出,双原子H₂的振动激发和转动激发显著提高了反应活性. 同时积分散射截面的理论值与前人的实验值相符合.     

Theoretical study of the A 3 0 + ← X 1 0 + and B 3 1 ← X 1 0 + transitions in the Cd-rare gas van der Waals molecules

Excitation spectra arising from A ³ 0 ⁺ ← X ¹ 0 ⁺ and B ³ 1 ← X ¹ 0 ⁺ electronic transitions in the Cd-rare gas (RG) van der Waals molecules are calculated using newly obtained theoretical potential curves for these species. In the molecular structure calculations, Cd²⁰⁺ and RG⁸⁺ cores are simulated by energy-consistent pseudopotentials which also account for scalar-relativistic effects and spin-orbit (SO) interaction within the valence shell. Potential energies in the Λ S coupling scheme have been obtained by means of ab initio complete-active-space multiconfiguration self consistent-field (CASSCF)/complete-active-space multireference second-order perturbation theory (CASPT2) calculations with a total 28 correlated electrons, while the SO matrix has been computed in a reduced CI space restricted to the CASSCF level. The final Ω potential curves are obtained by diagonalization of the modified SO matrix (its diagonal elements before diagonalization substituted for the corresponding CASPT2 eigen-energies). The spectroscopic parameters for the ground and several excited states of the Cd-RG complexes deduced from the calculated potential curves are in quite reasonable agreement with available experimental data. In addition, the radial Schr?dinger equation for nuclear motion was solved numerically with the calculated potentials to evaluate the corresponding vibrational levels and radial wavefunctions. The latter have been used in the calculation of the appropriate Franck-Condon factors to yield information on relative intensities of the vibrational bands of the Cd-RG complexes. The theoretical vibrational progressions are discussed in the context of experimental spectra. Received 10 August 2000 and Received in final form 7 November 2000     

CP -violation effects in the decays B ? → D * K *? and method for determining the weak phase γ

A method for determining the angle γ and the ratio of the amplitudes A _λ(B ⁻ → K ^*−) and A _λ)B ⁻ → D ^*0 K ^*−), r _Bλ, for all three vector-meson polarization states by using the decays B ^∓ → D ^* K ^*∓ is proposed. This method relies on the interference between the decays B ⁻ → D ^*0 K ^*− and B ⁻ → K ^*−, which arises if D ^*0 and decay to D ⁰/ π ⁰ and D ⁰/ γ, whereupon D ⁰ and mesons decay to common final hadron states. The doubly Cabibbo-suppressed modes of D ⁰-meson decay are chosen here to specify such final states. Original Russian Text ? V.A. Kovalchuk, 2007, published in Yadernaya Fizika, 2007, Vol. 70, No. 4, pp. 754–763.     

Perturbations in the A1Π-X1Σ+ system of the BeO molecule

All perturbations observed by Lagerqvist (Thesis, University of Stockholm, 1948) in the A¹Π-X¹Σ⁺ transition have been assigned to a³Π₂, a³Π₁, and X¹Σ⁺ states. Vibrational and rotational constants of the a³Π state as well as electronic parameters for A ～ X, A ～ a, and a ～ X interactions have been determined.