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1.
Using the technique of Doppler-free two-photon spectroscopy the energies of the n2S (12 ? n ? 35) and n2D, (11 ? n ? 48) states of CsI have been measured with a thermionic detector. The absorption spectrum of molecular iodine was used as a reference giving us a total estimated accuracy of about 2 × 10-7. Taking also into account the energies of the 7–11 2S and 5 and 6 2D, states measured by other authors and using an extended Ritz-formula we found the ionization limit to be Ei = 31406.468 ± 0.006 cm-1. 相似文献
2.
The decay of the 4G state of Nd3+ in LaCl3 and La(Cl99.6 Br0.4)3 was measured after pulsed laser excitation as a function of temperature. The decay rate is shown to depend besides the radiative transition on single-phonon relaxation between the states 4G () and 4G () and on multiphonon orbit-lattice relaxation from 4G to 2G. Partial substitution of Cl by Br only alters the radiative lifetime. 相似文献
3.
J. Migdałek W.E. Baylis 《Journal of Quantitative Spectroscopy & Radiative Transfer》1979,22(2):113-125
Relativistic, single-configuration Hartree-Fock oscillator strengths for the lowest ns2S→np2P and np2P→nd2D transitions in the first few members of the silver (n = 5) and gold (n = 6) isoelectronic sequences have been studied, both with and without allowance for core polarization. Core polarization is included by introducing a polarization potential in the one-electron Hamiltonian and by employing the corresponding correction for the dipole-moment operator in the transition matrix element. The results obtained are compared with available experimental data and the influence of core-polarization effects on oscillator strengths is discussed. 相似文献
4.
Optical measurements on crystals in the series SnSxSe2?x for 0 ? x ? 2, have yielded information on the changes in the ordinary refractive index and the energy gap in the temperature range 125–425 K. The coefficient has values +40 to +160 × 10?6K?1 and this confirms that covalent bonding predominantly exists in these materials. The coefficient remains fairly consistent for all values of x with an average value of -8.0×10-4eV K-1. 相似文献
5.
Z. Strachman H. Braun J.P. Gerber G. Maurer A. Michalon B. Schiby R. Strub 《Nuclear Physics B》1975,98(1):120-136
A new approach to the t-channel isospin analysis of ZN → Z′(Nπ) reactions is presented. This approach, useful for when only five independent sets of data are availables, is used to analyse data of reactions obtained in a experiment at experiment at 5.5 GeV/c. the t behaviour of the different isospin exchange amplitudes, suggests their exchange mechanism production. The mass spectrum, MπN, of the contributions produced by exchanged isospin Iex = 1, shows enhancements corresponding to N(1490) N(1670) and Δ(1230) isobars, while the mass spectrum for Iex = 0 presents only a large bump at ~1350 MeV commonly identified as N1(1400). 相似文献
6.
M.J. Corden J.D. Dowell D. Eastwood J. Garvey R.J. Homer M. Jobes I.R. Kenyon T. McMahon R.J. Vallance P.M. Watkins J.A. Wilson J. Gago M. Jung P. Sonderegger D. Treille P.L. Woodworth V. Eckardt J. Fent K.C.T.O. Sumorok 《Physics letters. [Part B]》1977,68(1):96-100
Measurements have been made of relative production cross sections of the by π±, K±, p and p? at 39.5 GeV/c incident on copper. production rates from π?, K? and p? are similar. The relative particle/anti-particle production cross sections for x>0 are , σ(K+)/σ(K?)=(0.85±0.5) and . The small p/p? cross section ratio disagrees with models of J/ψ production by gluon amalgamation. 相似文献
7.
A general spin S Ising chain interacting with a single phonon mode of the harmonic lattice is studied. The thermodynamics of the spin system is calculated exactly for S = 1, and , while self-consistent equations for the induced lattice distortions are derived. It is demonstrated that for S > there is no second-order phase transition, in contrast to the case S = which was proved to have a tricritical point. This is found to cohere with the previous studies of the dimerized magnetic model chains. 相似文献
8.
Takashi Okazaki Seiji Ōkubo Yūichi Hoshino Kanji Fujii 《Physics letters. [Part B]》1979,85(1):107-110
The validity of the assumption that decays into mesons proceed via ω, φ and ?0 poles followed by cascade decays is examined. is well reproduced by using and the B → ωπ helicity structure. The structure of OZI-violating transitions including the electromagnetic contribution is examined, and compared with the data on inclusive decay. 相似文献
9.
A.L.S. Angelis G. Basini H.-J. Besch R. Breedon L. Camilleri T.J. Chapin R.L. Cool P.T. Cox C. von Gagern C. Grosso-Pilcher D. Hanna J.T. Linnemann C.B. Newman R.B. Nickerson N. Phinney S.H. Pordes K. Powell J.M. Yelton 《Physics letters. [Part B]》1982,116(5):379-382
The invariant cross sections for π0 meson production in alpha—alpha and alpha—proton collisions at the ISR were meas- ured up to transverse momenta of and , respectively. These measurements are compared with π0 production in pp collisions at the same values of nucleon, and the variation of the nuclear A-dependence with pT is determined. 相似文献
10.
The vector polarization transfer coefficient Kyy′ and the tensor analyzing power Azz have been measured for the 2H()3He reaction at θ = 0° over an incident deuteron energy range from 1 to 15 MeV in 0.5 MeV steps. The results agree with the previous 2H()3He measurements of Simmons et al. and are nearly identical to the 2H()3H measurements of Clegg et al. in the region of overlap. The present results provide an accurate and complete set of the observables necessary to use the 2H(,)3He reaction as a source of polarized neutrons. 相似文献
11.
K. Böckmann H.G. Heilmann U. Idschok P. Kobe F. Selonke V. Blobel H. Fesefeldt B. Hellwig D. Mönkemeyer H. Franz P. Freund W. Schrankel 《Nuclear Physics B》1974,81(1):45-60
The reaction pp → nucleon + nucleon + pion at 12 and 24 GeV/c is analyzed in terms of the isospin amplitudes for the production of the (Nπ) system. The energy dependence of the amplitude is weak, while the contribution shows the strong energy dependence known from meson exchange reactions. The slope parameter B of the dσ/dt′ distributions of the contribution is a strong function of the (Nπ) mass, decreasing sharply from about 12 GeV?2 at threshold to about 4 GeV?2 above 1700 MeV. Comparing our results for the cross section with those of similar investigations in πp and Kp reactions, we find that factorisation is valid within experimental errors. The results support the conclusion that the contribution is dominated by diffraction dissociation of the proton. 相似文献
12.
Features of diffractive scattering and the nature of the N1(1400) observed in reactions at 5.7 GeV/c
Z. Strachman 《Nuclear Physics B》1976,107(2):330-338
The results for the diffractive scattering contribution () obtained in a cross channel isospin analysis of the reactions at 5.7 GeV/c are compared with those obtained for other ZN → Z′(Nπ) reactions where Z stands for N, π and the carbon nucleus. The dependence of the diffractive scattering on the mass MπN and the momentum transfer t seems very weakly related to the nature of Z and the incident momentum.A comparison between amplitudes of the isospin exchange Iex = 0 and Iex = 1 leading to production shows that and are produced essentialy through Iex = 1. 相似文献
13.
N. Kawamura K. Iura Y. Kimura K. Katsube M. Kikuchi S. Ali S. Hayashibe T. Ishimatsu M. Fujioka K. Abe 《Nuclear Physics A》1983,406(3):533-540
The nuclear g-factor of the 4498 keV + isomeric state in 63Cu was measured with the in-bearn perturbed angular distribution method, through the 62Ni(α, p2nγ)63Cu reaction, to be gexp = 0.184 ± 0.012. This value is in good agreement with a semiempirical g-factor for the three-quasiparticle configuration [π2p(v1f, 1g)7]+ calculated using the experimental single-particle g-factors of neighbouring nuclei. At the same time the internal magnetic field at the Cu nuclei in Ni metal was obtained to be Bint = ?46.6 ± 1.3 kG. 相似文献
14.
In reactions such as e → anything, N → anything, the final state (neglecting secondary isospin violating decays) is customarily supposed to have isospin zero or one. We show that for such states the average fraction (X) of the energy carried away by neutral pions is bounded by , when I3 = 0 (e.g., for ee, pp, nn) and by , when I3=±1 (e.g., for pn or np). 相似文献
15.
H. Laven G. Otter G. Rudolph R. Klein H.J. Schreiber D.J. Kocher D.R.O. Morrison P. Schmid K.L. Wernhard R.M. Eason T.C. Bacon K.W.J. Barnham P.J. Dornan B. Pollock J. Macnaughton M. Markytan 《Nuclear Physics B》1977,127(1):43-56
The reactions (1) K?p → K+K?Λ and (2) have been studied on samples of 109 and 64 events, respectively, at 10 GeV/c and 125 and 69 events at 16 GeV/c, reasonably free from contaminations. The investigation of the first reaction uses also 84 events of the final state at 10 GeV/c. Analysis of the Van Hove plots indicates that the K+K?Λ and final states are produced by two main mechanisms: (i) a ΔQ = 0 process, with a strong diffractive component near threshold, involving the dissociations p → K+Λ in reaction (1) and in reaction (2) and (ii) a ΔQ = 1 process involving hypercharge exchange, and producing K+K? and systems in reactions (1) and (2), respectively, recoiling off the Λ. With increasing energy, this hypercharge exchange process decreases slowly when K+K? is produced, but fast where the production of , violating the Zweig rule, occurs. 相似文献
16.
Energy levels in the N = 83 nucleus 149Dy were studied by the reaction 152Gd(α, 7n) at 106 MeV bombarding energy using in-beam γ-ray spectroscopy methods. The measurements identified three isomers in this nucleus, at 1073 keV (13 ± 3 ns), at 2700±150keV (5 μs < T < 0.5 s), and above 3.5 MeV (50 ± 15 ns). The low-lying isomer is interpreted as i. The configuration ?(πh2)10+ ×vf is suggested for the state at 2.7 MeV. 相似文献
17.
We consider possible effects that may invalidate the method in some statistical and field models. Discussion is in the framework of the model of charged, non-relativistic fermions with N-component spin. The static dielectric function ?(q, 0) is predicted to have a pole in N. The real parameter of the expansion is shown to be an increasing function of the coupling constant. 相似文献
18.
The deviations from the exponential decay law of the states of the Dirac hydrogen atom with respect to the transition are numerically estimated. We find |a0(t) ? exp(?λt)|?2.5 × 10?4 for all t, where a0(t) is the “exact” decay amplitude and λ is a complex constant such that (2Re λ)?1 is the “natural lifetime” of the states with respect to the spontaneous transition to . 相似文献
19.
noise dependence on temperature for both n- and p-type silicon has been measured. The formula for calculation of noise is presented. The formula has been derived by presumption that only lattice scattering gives noise. A good agreement between calculations and experimental results is found. 相似文献
20.
John W. Tromp Robert J. Le Roy Simon Gerstenkorn Paul Luc 《Journal of Molecular Spectroscopy》1983,100(1):82-94
The disagreement of Danyluk and King's (Chem. Phys.25, 343 (1977)) rotational constants for levels lying near the dissociation limit of B-state I2 with the mechanical behavior predicted by near-dissociation theory is investigated. The discrepancies are shown to be much too large to be explained by either the neglect of centrifugal distortion effects in the original analysis or by rotational or spin-rotation coupling to a nearby repulsive 1u state. These differences are therefore attributed to experimental error, a conclusion which is confirmed by more recent experimental results. A reanalysis of the best available data for levels near the dissociation limit of B-state I2 then yields improved values for the B-state dissociation limit = 20 043.16 (±0.02) cm?1 of the vibrational index at dissociation v = 87.32 (±0.04) and of the long-range potential constant . This in turn implies a slightly improved ground-state dissociation energy of 0 = 12 440.18 (±0.02) cm?1. 相似文献