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1.
The (292.7 nm) M1 transition in Tl is observed and its matrix element is measured. Tl vapor is illuminated by a pulsed linearly polarized laser beam (λ = 292.7 nm). Interference between m and the Stark-induced E1 amplitude in finite electric field E results in circular polarization of 535 nm fluorescence proportional to m/E, which is detected. The result is m = ?(2.11 ± 0.30) × 10?5 | eh/2mec| in agreement with theory. The ultimate goal of this research is to detect parity violation in the neutral weak interaction by observation of a helicity dependence in the absorption when the laser light is circularly polarized. 相似文献
2.
The radiative lifetimes of the 6p2P levels in Hg(II) have been measured to be ns and ns by the beam-gas-Hanle and the beam-foil techniques, respectively. The result for the level differs from recent theoretical calculations, whereas there is good agreement for the level. 相似文献
3.
Hyperfine structure of the (0, 0, 1) - (1, 0, 1) transition of methanol has been investigated by beam absorption and of the (J, 1, 3?) → (J, 1, 3+) transitions for J = 2, 3, and 6 by beam-maser spectroscopy. The best-fit results for the spin-rotation and spin-spin coupling constants and , respectively, are in kHz1: , , , , , and (. 相似文献
4.
The time dependence of microwave absorption was measured for the J = 2-1 and J = 3-2 transitions of OCS under on- and off-resonant conditions utilizing Stark and source modulation, respectively. The two effective pressure parameters obtained under the two conditions, which correspond to and , respectively, according to the Bloch equation, are different beyond experimental error; the difference is 0.94 ± 0.38 (2.5σ) MHz/Torr for J = 2?1. This difference was also determined to be 1.19 ± 0.30 MHz/Torr from the dependence of the nutation frequency on the microwave power. 相似文献
5.
We use semiclassical methods to discuss the scaling behaviour of quarkonium level splittings up to . Special emphasis is laid on the effects of asymptotic freedom which are found to be essential for . The bound t system will almost look like the ? system except that is larger than 0.8. In the ? system R will already be close to 0.8. 相似文献
6.
We describe the optical absorption spectrum of a single crystal of Gadolinium Molybdata (GMO) at the temperature of liquid helium. We observe a set of sharp lines in the near ultra violet region; we clasify the lines into three groups A, B, and C. We study the positions of the lines as functions of the orientation of the crystal relative to the polarization of the incident light and we investigate the Zeeman effect on the lines of the groups A and B. We suggest that the observed lines of all three groups are due to transitions between the ground state and the excited , and states of the Gd3+ ion in the crystal. 相似文献
7.
Using Doppler-free two-photon absorption, we have measured the hyperfine splittings (hfs) and isotope shifts of the 72P states of natural thallium. We obtain , and . Surprisingly, the 72P state hfs is larger than that of the 62P state. 相似文献
8.
L Nemes 《Journal of Molecular Spectroscopy》1978,72(1):102-123
Medium resolution infrared grating spectra of gaseous ketene, H2CCO were recorded between 1000 and 400 cm?1, both at instrument temperature (40°C) and with cooling (?40°C). Interferometric Fourier spectra were also measured at ?70°C with resolution 0.22 cm?1 between 450 and 330 cm?1. The K structure of the fundamentals ν5, ν6, ν8, and ν9 was assigned. These fundamentals are coupled by a-axis Coriolis interactions. These couplings were analysed on the symmetric top basis for setting up the perturbation matrix and by utilizing the K-dependent Coriolis shifts of levels. A preliminary analysis of the Coriolis intensity anomalies was also undertaken.Band center values from combination differences are and . Synthetic spectra indicate the band origins of ν8 and ν9 to be close to 977.8 and 439.0 cm?1, respectively. Estimates of Coriolis coupling constants obtained from synthetic spectra are , , , and . Approximate ratios of unperturbed vibrational transition moments obtained from spectral simulations are . 相似文献
9.
This paper reports the first measurements of pressure broadening and shift of thallium 6 transitions by N2 and He perturbers. Ion-detection with box-car integration was used for data collection. The number of the perturbating gases ranged from . The red shift to N2 and the shift due to He are found to vary linearly with pressure. The value of the effective cross section for the impact broadening was determined and van der Waals constants obtained. 相似文献
10.
J.N. Le Toulouzan R. Darrigo P. Valentin 《Journal of Quantitative Spectroscopy & Radiative Transfer》1974,14(12):1239-1252
We describe the results of measurements on emission and absorption of potassium I lines obtained in two series of experiments. The first concerns a low-pressure flame fed by a methane and oxygen mixture, seeded with potassium carbonate, and the other an atmospheric- pressure helium plasma seeded with potassium.A collation of the experimental results of the latter series and Drawin's theory about the conditions of validity for local thermodynamic equilibrium show that the transition-probability values measured by Heiërman are incorrect. Warner's theoretical values are more satisfactory. This study allows us to propose new oscillator strengths for the KI lines corresponding to the following transitions: , of the sharp series and of the diffuse series. 相似文献
11.
C.-J. Lorenzen K. Niemax 《Journal of Quantitative Spectroscopy & Radiative Transfer》1979,22(3):247-252
The energies of the and levels of CsI have been redetermined photographically from high resolution absorption measurements of the principal series lines X. The new data disagree significantly [ ≈0.13 cm-1] with the values given in the NBS-Tables of Moore1 which are taken from a paper by Kratz.2 By means of an extended Ritz-formula, the ionization energy of CsI was found to be 31406.46±0.03 cm-1, which is, within the limit of uncertainty, in agreement with the data of Kleiman,3 Eriksson et al.,4 Bockasten,5 and Eriksson and Wenåker.6 相似文献
12.
Dependence of static dielectric susceptibility and correlation length of charge density waves (CDW) with weak defects on parameter of incommensurability with lattice is investigated. In almost commensurate phase (h?hchc), and Rc ~ (h ? hc). In. Far from commensurability , , where a is the dimensionless ratio of random potential intensities, corresponding to backward and forward scattering impurities. 相似文献
13.
Measurements of the lifetimes of the and levels of Cs are described. The populations of these excited levels were produced by using a tunable dye laser. The fluorescence signals from a gated photomultiplier were recorded by analog sampling. The results of the measurements are 133±2 and 155±4 ns for the 7 levels, respectively. 相似文献
14.
N. Kimura 《Nuclear Physics B》1984,246(1):143-156
Masses of all the glueballs which are created by 6- or 7-link operators are calculated to order g?8 in pure SU(3) hamiltonian lattice gauge theory. Several low-lying states are found with masses (1 and 7 stand for radial excitations and ms is the mass of the lowest 0++ state), . These values are obtained at the point g?2 ? 0.8, which lies near the scaling region. 相似文献
15.
H. Kleinert 《Physics letters. [Part B]》1976,62(1):77-80
In quark gluon theory with very small bare masses, -ψ, spontaneous breakdown of chiral symmetry generates sizable masses Mu, Md, Ms, … We find (. Scalar densities have well determined non-zero vaccum expectations at an SU(3) breaking of the vacuum c′ ≡ 〈0|u8|〉/〈0|uo|0〉 ≈ ? 16% 相似文献
16.
Peter Zimmermann Theodore W. Ducas Michael G. Littman Daniel Kleppner 《Optics Communications》1974,12(2):198-201
We present a new technique for selectively populating excited states which are inaccessible by dipole excitation from the ground state. The method uses a static electric field to introduce a component of a dipole-allowed state into the state of interest. We have applied the method to cesium to measure lifetimes and a Stark mixing coefficient. The results are , , and <62D|;ez |72P>/(E7P?E6D)=0.7(3)×10?3 where is in kV/cm. 141 相似文献
17.
The systematics of particle-hole states in the 2s-1d and shells have been analyzed in terms of the Bansal-French-Zamick weak coupling method. States considered are , the jn components corresponding to even-even ground states. 相似文献
18.
In this note we determine the oscillator strengths for the dipole absorption of neutral bound excitons in direct gap semiconductors, using our previously obtained 35-term Page and Fraser type wave function, and taking into account the detailed electronic structure as well as the electron-hole exchange interaction.The envelope part of the oscillator strengths varies considerably with the electron-hole mass ratio , and is maximum for the (D0, X)- complex when σ = 0.4. For typical σ-values (σ? 0.1–0.2), . But when σ approaches zero, the overlapping of the electron and the hole envelope wave functions of the (A0,X)-complex decreases progressively so that the oscillator strength also decreases and tends to zero.In the case of zinc-blende materials (Td) and positive spin-orbit coupling at , we confirm that the line strength for transitions to or from or level of the (A0, X)-complex is equal to one quarter of the line strength to or from the level.In the case of CdS, where our computed values are only in qualitative agreement with the experimental values, we discuss the use of the phenomenological result of Rashba. 相似文献
19.
Emission spectra for the electronic transitions and of He2 are reported and the electronic structures of and characterized. The energy levels associated with exhibit extensive channel mixing, which leads to a breakdown of conventional band models for the higher n1-members of these Rydberg “series.” However, a model based on multichannel quantum defect theory quantitatively correlates the observed level structures. The higher-energy () portions of the channels can be represented by two eigen-quantum defects μ1 = 0.225 and μ2 = 0.930 and the close- to loose-coupling matrix elements and . The inclusion of energy dependence in the μα's leads to quantitative correlations for all n1-values. 相似文献
20.
Excitation functions at θ = 90° have been measured for , , and , in the range E3He = 3–19 MeV. The first reaction has also been studied at θ = 40°. Excitation functions at 90° have also been measured for and for E3He = 19–26 MeV. Angular distributions have been measured for the first four reactions.For the most excitation functions, a broad peak is observed, several MeV wide, centred at about Ex≈ 20 MeV. Superimposed on this, in some cases, are narrower peaks, with width ≈ 1 MeV. Energies and widths have been extracted for all resonances.Cluster-model calculations have been carried out, using methods similar to those which have proved successful for low-lying states in A= 18–19 nuclei. No satisfactory correspondence with the present results was found. The shell model has been used to calculate Γ3He and Γγ for 1?ω excitations in the final nuclei. These generally show good agreement with the trends of the experimental data. The results are consistent with the excitation of the giant dipole resonance in 3He capture, but much more weakly than in proton capture. 相似文献