共查询到20条相似文献,搜索用时 39 毫秒
1.
Takashi Tonegawa 《Solid State Communications》1981,40(11):983-986
The transverse spin pair correlation function pxn=<SxmSxm+n>=<SxmSxm+n> is calculated exactly in the thermodynamic limit of the system described by the one-dimensional, isotropic, spin-, XY Hamiltonian . It is found that at absolute zero temperature (T = 0), the correlation function ρxn for n ≥ 0 is given by , , where the plus sign applies when J is positive and the minus sign applies when J is negative. From these the asymptotic behavior as n → ∞ of |?xn| at T = 0 is derived to be with a = 0.147088?. For finite temperatures, ρxn is calculated numerically. By using the results for ?xn, the transverse inverse correlation length and the wavenumber dependent transverse spin pair correlation function are also calculated exactly. 相似文献
2.
Discharges through mixtures of helium and neon show two band groups near 4250 and 4100 Å as first observed by Druyvesteyn. These bands, assigned to the HeNe+ ion by Tanaka, Yoshino, and Freeman, have been studied under high resolution and have been fairly completely analyzed. The upper state of the transition is a very weakly bound state resulting from . There are two lower states resulting from the two components of . The upper of these two () is also very weakly bound while the lower of the two, the 2Σ+ ground state, has a dissociation energy of 0.69 eV and an re value of 1.30 Å. All bands in both band groups show four branches designated Rff, Qef, Qfe, and Pee. From their analysis the rotational constants in the various vibrational levels of the three electronic states have been determined. While no spin splitting in the B2Σ+ state has been found the ground state X2Σ shows a very large spin splitting and the state a very large doubling. The vibrational numberings in all these states were established by the study of the spectrum of 3HeNe+. At the same time the hyperfine structure observed in all lines of 3HeNe+ confirmed the nature of the upper state B2Σ+ as resulting from He+ + Ne, i.e., by charge exchange from the ground state. The component of the 2Π state has not been observed, presumably because of low intensity. 相似文献
3.
H. Taureg G. Zech F. Dydak F.L. Navarria P. Steffen J. Steinberger H. Wahl E.G.H. Williams C. Geweniger K. Kleinknecht 《Physics letters. [Part B]》1976,65(1):92-96
The branching ratio has been determined to be (2.68±0.15)×10?3 for photon energies greater than 50 MeV in the KS0 rest frame. The decay KS0→π+π?γ is found to be dominated by the internal bremsstrahlung transition. The branching rato of a possible direct transition is found to be less than 0.06 × 10?3 at 90% confidence level for . 相似文献
4.
H. Braun M. Cornelssen H.-U. Martyn O. Erriquez S. Natali F. Romano D. Bertrand M. Csejthey-Barth J. Lemonne P. Renton P. Vilain D.C. Cundy T.I. Pedersen D. Waldren 《Physics letters. [Part B]》1973,47(2):185-188
The q2 variation of the factor in the decay K+→π0e+ν has been studied using a sample of even detected in the CERN 1.1 m3 heavy-liquid bubble chamber. The data are consistent with a linear development with λ+=0.027±0.008. 相似文献
5.
Marek Danielewski Jaeosław Da̧bek Stanisł;aw Mrowec Grażyna Siemińska 《Solid State Ionics》1985,17(4):331-335
Using the re-equilibration kinetic method the chemical diffusion coefficient in nonstoichiometric chromium sesquisulfide, Cr2+yS3, has been determined as a function of temperature (1073–1373 K) and sulphur vapour pressure (10?104 Pa). It has been found that this coefficient is independent of sulphur pressure and can be described by the following empirical equation: . It has been shown that the mobility of the point defects inCr2+yS3 is independent of their concentration and that the self-diffusion coefficient of chromium in this sulfide has the following function of temperature and sulphur pressure: . (cm2s?1). 相似文献
6.
The emission spectrum of the He2 molecule has been rephotographed in the ~4000–~5700 Å region and the , , and transitions analyzed. The 4dδj3Δu, 4dπj3Πu, and states have been characterized through v = 2 and the 4dδJ1Δu, 4dπJ1Πu, , and states for v = 0. The term levels for these perturbed and l-uncoupled states have been confirmed (a) by analyses of bands with common levels from Δv = 0, ±1 sequences and (b) by analyses of the transitions between the above states from 4d and 4s and the and states associated with 3pσ. Molecular constants are reported which have been partially corrected for the effects of l-uncoupling and the homogeneous perturbations between the state pairs J, H and j, h. 相似文献
7.
Masuo Suzuki 《Physics letters. A》1985,113(6):299-300
It is proved that the trace of the generalized Trotter formula is an even function of n, when all Aj are symmetric, namely Atj = Aj, togethern with some generalizations. This yields a new extrapolatio n method of the form for large n in quanntum Monte Carlo simulations. 相似文献
8.
9.
Line positions and molecular constants for the 0-0, 1-0, 2-0, 0-1, 2-1, 3-1, 0-2, 1-2, and 4-2 bands of the C2 Phillips system () are reported. Among them, five bands have not been reported previously. Rotational perturbations have been observed in the previously unobserved v = 1 level of the state. This state is perturbed by the state which was discovered by Ballik and Ramsay. These observations provide new information regarding the perturbing state. In particular, the minimum of the potential energy for the state has been found to be at 9227.4 cm?1 instead of 13 310 cm?1, which was the previous Te value for this electronic state. 相似文献
10.
Harry Partridge Charles W. Bauschlicher James R. Stallcop 《Journal of Quantitative Spectroscopy & Radiative Transfer》1985,33(6):653-655
Potential energy curves for the , and states of N+2 that dissociate to N () and , have been determined from a complete active space self-consistent field calculation. The state is found to be significantly bound (De = 2.68 eV) with a minimum at 1.72 Å. 相似文献
11.
The emission and excitation spectra of the aromatic thioketone xanthione have been measured in Shpolskii matrices at 15 K. Under these conditions a sharp and rich vibrational structure is observed in the lowest triplet and the first and second excited singlet states. The phosphorescence excitation spectrum places the origin of the T1 ← S0 transition at 15 143 cm?1, while that of the absorption is tentatively assigned to the band at 16 093 cm?1. The phosphorescence spectrum, which shows only a weak CS stretch vibrational band, is dominated by ring vibrations. In accordance with the previous analysis of ODMR measurements, it is suggested that T1 and T2 states are energetically very close, thereby resulting in a lowest triplet state of heavily mixed n, , character. No mirror-image relationship is found between the relatively strong S2 → S0 fluorescence and the excitation spectrum of the transition. The latter is dominated by a long, pronounced 336-cm?1 progression. 相似文献
12.
D. Stauffer 《Solid State Communications》1976,18(4):533-535
Usual theories for time-dependent effects in superparamagnetism (over-turning of large spin clusters) assume a flip rate ∝ exp (-U/kT). Instead, following Lifshitz and Kagan, we calculate the flip rate due to quantum-mechanical zero-point motion. The resulting “zero temperature” flip rate is R0 exp (-cn) for a cluster with n spins. R0 and c depend on domain wall energy and mass; typically, and c = 1. 相似文献
13.
From a study of (p,t) reactions on 31P and 30Si it is suggested that in 29P the states with and , the pair , , and the pair , are related by weak coupling of a s proton with the states 01+, 02+, 21+ and 41+ respectively of 28Si. Completely atypical L = 2 angular distributions have been obtained for the and states in 29P and it is suggested that this is due to contribution by two-step processes. 相似文献
14.
G.V. Dass 《Nuclear Physics B》1973,59(1):324-332
If resonance decaying into KS,L (the short- and long-lived kaon) and a neutral system So of pions, one can isolate the C-even and C-odd, crossed-channel contributions to by using the reactions whether So is a C-eigenstate, or a mixture of C-even and C-odd states. Applications to the production of K1(890) and the Q-meson are discussed, and simple numerical predictions made for QS,L production. Q-production data indicate approximate t-channel helicity conservation for the ω and P' exchanges at vertices involving a spin change, in similarity to the belief for the pomeron. QS,L production data can give information also on Q-decays. 相似文献
15.
The nature of mesons in the 0++ nonet is studied. In particular we discuss the parameterization of the I = 0 S wave in terms of the S1 and possible ? mesons. The S1 parameters are determined by fitting to π?π+ and K?K+ production data. In particular we find . 相似文献
16.
Zinc and cadmium atoms have been condensed with argon and krypton at 10 K. The most intense absorption is due to the atomic transition, and a weak band is due to the atomic absorption. Structured absorptions at 252 and 254 nm in solid argon and krypton with vibrational spacings of 140-120 cm?1 are due to the transition of Zn2. Similar 273 and 277 nm absorptions with 110-90 cm?1 vibrational spacings are due to Cd2 in solid argon and krypton, respectively. 相似文献
17.
J.C.D. Brand U.D. Deshpande A.R. Hoy S.M. Jaywant 《Journal of Molecular Spectroscopy》1983,100(1):143-150
The E-B (0g+-0u+) band system of Br2 has been investigated at Doppler-limited resolution using polarization labeling spectroscopy. Merged E state data for the three naturally occurring isotopes in the range vE = 0–16, expressed in terms of the constants for 79Br2, are (in cm?1) Y0,0 = 49 777.962(54), Y1,0 = 150.834(22), Y2,0 = ?0.4182(28), Y3,0 = 6.6(11) × 10?4, Y0,1 = 4.1876(28) × 10?2, Y1,1 = ?1.607(16) × 10?4, and Y0,2 = 1.39(39) × 10?8. The bond distance is , and the diabatic dissociation energy to . 相似文献
18.
B. Fant T. Weckström T. Lönnroth C.J. Herrlander K. Honkanen A. Källberg 《Nuclear Physics A》1984,429(2):296-312
Levels in 208At were populated in the 209Bi(α, 5n) reaction, and the subsequent radiation was studied using γ-spectroscopic methods including γ-ray excitation function and angular distribution, γγ(t) coincidence and γt measurements, as well as measurements of conversion electrons. The excited spectrum of 208At is found to consist of two almost disconnected parts which are proposed to originate from seniority-three proton and neutron cascades. Two isometric states are observed. A state at 1090 keV is proposed to have the main configuration and Jπ = 10?. A high-spin isomer with is assigned to be the state. Shell-model arguments are used to assign configurations to most of the observed levels. Transition rates are discussed. 相似文献
19.
A theoretical model used to describe the and B3Πg states of N2 is presented. Using recently acquired high resolution spectra of the (0-0) band, rotational energy levels of the v = 0 vibrational levels of these two states are generated with this model. These levels are in excellent agreement with those obtained using a combination differences technique. The precision of the model generated levels is 0.01 cm?1. The previously unpublished rotational levels of Dieke and Heath for the , B3Πg and C3Πu states are referenced to the (v = 0, J = 0) ground level and tabulated here. Estimates of the precision of their work are made. 相似文献
20.
Richard Brower 《Nuclear Physics B》1981,190(4):699-718
In lattice gauge theory, many computations such as the strong coupling expansions, mean field theory, or the few plaquette models require the evaluation of the one-link integral in the presence of an arbitrary N × N complex matrix source (J). For SU(N) gauge theories, we express our general solution to the external field problem as an integral over the maximal abelian subgroup [U(1)]N?1 where S0 = 2Σkzk cos(φk ? θ), zj are eigenvalues of √JJ+, e2iNθ=detJ/detJ+, and G is an appropriate jacobian determinant. Our explicit solution follows from differential Schwinger-Dyson equations cast in a separable form by using fermionic variables, and the special cases of N = 2, 3 and ∞ agree with earlier derivations. 相似文献