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1.
The contributions of the superposition of configurations ns 25d 76s+ns5d 76sn′s+ns5d 76s 2 (n=1–5, n′=7–10) to the parameters of the hyperfine structure a 5d 01 , a 5d 12 , a 5d 10 , a 6s 10 in the spectrum of the osmium atom Os I are calculated. Nonzero contributions are shown to be made only to the parameters a 5d 10 and a 6s 10 . This fact justifies the inclusion of the parameter a 5d 10 in the semiempirical analysis of experimental values of magnetic dipole constants of the hyperfine structure of the 5d 7 s configuration in the spectrum of the osmium atom. The effect of nucleus volume on the parameters of the hyperfine structure in the spectra of osmium isotopes 187Os and 189Os is estimated.  相似文献   

2.
Starting from an isospin invariant shell-model hamiltonian, we describe a method for deriving microscopically the IBM-hamiltonian appropriate to lights d-shell nuclei. The key ingredients of our approach are:a) the Belyaev-Zelevinsky-Marshalek (BZM) bosonization procedure;b) two successive unitary transformations that extract the “maximally decoupled” collective bosons with angular momentaJ=0(s ππ + ,s νν + ,s πν + ) andJ =2(d ππ + ,d νν + ,d πν + (T=0),d πν + (T=1)). The method is applied to obtain the low-energy spectra and the electron scattering form factors for the 0 1 + →2 1 + transitions in20Ne and24Mg. Good agreement with the exact shell-model results is achieved. The inclusion of proton-neutron bosons (s πν + ,d πν + (T=1),d πν + (T=0)), as well as the renormalization of boson parameters due to the non-collective degrees of freedom, are shown to play a crucial role.  相似文献   

3.
A method of simultaneous parametrization of one- and two-body interactions on atomic hyperfine structure of configurationl N is proposed and applied for the analysis of the configuration (6p)3 in the bismuth atom. For this purpose, the hyperfine structure splittings of the levels2D 3 2/0 ,2D 5 2/0 and2P 1 2/0 were measured. The finally obtained values of HFS parameters are: for one-body parameters (in MHz):a p 01 =2,537(9),a p 12 =5,182 (12),a10=?2,019(10),b p 02 =?3,198(53),b p 11 =2,816(54); for two-body parameters (in MHz):x pp ′/01 ,2=284(3),x pp ′/12 ,2=581(5),x pf ′/12 ,2=170(70),x pp ′/02 ,2=?359(36),x pf ′/02 ,2=?33(100). The value of the quadrupole moment of the nucleus 83 209 Bi is also discussed.  相似文献   

4.
It is numerically shown that the groundstate of the Friedel problem (consisting of a conduction band and a dresonance), occupied with (n+ 1) electrons, can be written as Ψ = (A a 0 * +Bd*) Π v=1 n a v * Φ0, where a 0 * represents a localized conduction electron state, d* is the Friedel resonance state and Π v=1 n a v 8 Φ0 is a Slater determinant of n single electron states a t * , (Φ0 is the vacuum state). The a i * together with a 0 * are part of a full ortho-normalized basis of the conductions band.  相似文献   

5.
The ΛΛ 6 He and Λ 9 Be hypernuclei are treated as the S=0, T=0 (for the former) and S=1/2, T=0 (for the latter) bound states of the three-cluster systems ΛΛα and Λαα, respectively. The cluster-reduction method is used to solve the s-wave differential Faddeev equations for these systems. On the basis of the MT I–III model, the ΛΛ interaction potential is specified in the form $V_{\Lambda \Lambda } = \frac{2}{3}V_{NN} $ . Phenomenological potentials are used to describe Λα and αα interactions. The binding energies of the ΛΛ 6 He and Λ 9 Be hypernuclei and the parameters of low-energy Λ-hyperon and α-particle scattering on a Λ 5 He hypernucleus are calculated. It is shown that the proposed ΛΛ interaction potential makes it possible to reproduce faithfully the binding energy of the ΛΛ 6 He hypernucleus and that scattering in the Λ Λ 5 He system is similar to neutron scattering on a deuteron.  相似文献   

6.
We analyse the experiments [1–3] on the measurement of the pion electromagnetic formfactor in the time-like and space-like region using an expression with correct analytical properties and with the asymptotics predicted by QCD. The best fit values for the physical quantities (1) electromagnetic radius of the pion:r π 2 =0.466±0.002 fm2, (2) the mass and width of the ρ (770) and the ρ′ (1600) meson:m ρ=768±1 MeV,Г ρ=138±1 MeV,m ρ′=1546±26 MeV,Г ρ'=620±60 MeV; (3) the residuesg ρ m ρ 2 =0.676±0.003,g ρ′ m ρ′ 2 =?(0.644±0.009); (4) the ππ-scattering lengtha 1 1 =(0.1±0.01)m π ?3 .  相似文献   

7.
Two new di-nitrogen centers, which were labeled M2 and M3, were found together with known W7 and N4 centers in an unusual reddish-brown natural diamond. The following magnetic hyperfine interaction parameters (expressed in MHz) were determined for the two nitrogen atoms:A 1 (1) =117.95(5),A 1 (2) =A 1 (3) =84.48(5),A 2 (1) =7.1(1),A 2 (2) =A 2 (3) =6.6(1) for M2 andA 1 (1) =121.55(5),A 1 (2) =A 1 (3) =85.90(5),A 2 (1) =6.0(1),A 2 (2) =5.4(1),A 2 (3) =5.1(1) for M3. Hyperfine interaction tensors for the nitrogen atom N1 with a larger interaction have axial symmetry about the <111> direction, but those for the other nitrogen atom, N2, appear to be small, almost isotropic. Probable models of the M2 and M3 centers are suggested and discussed.  相似文献   

8.
Using the reactor-produced lanthanum isotope 57 137 La, the hyperfine structure (hfs) of the transition La I, 5d 2 6p z 4 G 11 2/0 ?5d 2 6s a 4 F 9/2, λ=6250 Å and La I, 5d 2 6p z 2 H 11 2/0 ? 5d 2 6s a 2G9/2, λ=6266 Å were measured by means of a Fabry-Pérot interferometer. The nuclear spin I (137La)=7/2, already theoretically estimated by earlier authors, was confirmed. The nuclear magnetic dipole moment μI(137La)=+ 2.690 (6) n.m. and the electric quadrupole momentQ(137La)=+ 0.26 (8) · 10?24 cm2 were determined from the ratios of the hfs interaction constantsA andB of137La and the natural139La.  相似文献   

9.
We analyze a discrete phenomenological model accounting for phase transitions and structures of polar Smectic-C* liquid-crystalline phases. The model predicts a sequence of phases observed in experiment: antiferroelectric SmC A * –ferrielectric SmC FI1 * –antiferroelectric SmC FI2 * (three-and four-layer periodic, respectively)–incommensurate SmC α * –SmA. We find that, in the three-layer SmC FI1 * structure, both the phase and the module of the order parameter (tilt angle) differ in smectic layers. This modulation of the tilt angle (and therefore of the layer spacing d) must lead to X-ray diffraction at the wave vectors Q s =2πs/d(s=n±1/3) even for the nonresonant scattering.  相似文献   

10.
We attempt to impose elastic unitarity on the forward π-π scattering using the Veneziano Amplitude together with a crossing symmetric subtraction term as an input. TheN/D method is used and thep, ? mesons are interpreted as CDD poles. The self consistency requirement led to the evalutation of the low energy parameters and theS andP-wave phase shifts. The values of the scattering lengths obtained area 0 0 =0.084m π ?1 ,a 2 0 =?0.024m π ?1 ,a 1 1 =0.047m π ?3 .  相似文献   

11.
The followingg-factors have been derived from time integral measurements of γ-γ angular correlations in the static magnetic hyperfine field of magnetized gadolinium metal probes:156Gd:g(4 1 + )=+0.310(19)g(6 1 + )=+0.25(21)g(4 3 + , 1511 keV)=+0.809(27)158Gd:g(4 1 + )=+0.409(15). The 5.35d 156Tb sources were produced by the reaction156Gd(d, 2n)156Tb in our cyclotron. A carrier-free 150y 158Tb source was obtained from ISOLDE/CERN. In comparison with the precisely knowng-factors of the 2 1 + states,g(2 1 su+ ,156Gd) =+0.386(4) andg(2 1 + ,158Gd)=0.381(4), we observe a large reduction for the156Gd 4 1 + state whereasg increases slightly for158Gd. The half-life of the 4 1 + state of158Gd was remeasured as158Gd:T 1/2(4 1 + )=148(2) ps. A measurement of the rotation in the 4 3 + state of156Gd in external magnetic fields of various strengths up toB ext=9.5 T did not confirm the anomalous dependence of the magnetic hyperfine field in gadolinium metal on the external field, which has been reported by Persson et al. [29].  相似文献   

12.
A comparative study is made of four three-parameter semiempirical potential energy functions for 32 electronic states of diatomic molecules and their ions:n 2:X1gS g + ,B 3πg,A 3 gSu,C 3 u,B′ 3 gSu.a 1 πg, a′gS u ? ,Ω 1δu N 2 + :X 2 gS g gS +A 2 π,C 2 gS u + ,B 2 gS u + CO:X1gS+,a 3 π, a′3 gSu,e 3 gS?,d 3gD1,A 1π CO+:X2gS+,A 2 π,B 2gS+ O2:X3gS g ? ,B 3 gSu,c 1 gS u ? ,b 1gS g s ,a 1 δg,c 3 δu O 2 + :X 2πg,A 2 πg, a1 πg,b 4 gS g ? A program for numerically integrating the radial Schrödinger equation by the Cooley method is worked out. Certain additional units are introduced to conserve computer time. The resulting vibrational levels are compared with the experimental levels for all the electronic states studied. It is concluded on the basis of this analysis that it is not possible to describe equally well all the electronic states of various molecules on the basis of any single three-parameter potential function. A method for choosing a potential function for describing some particular electronic state of a diatomic molecule is proposed.  相似文献   

13.
Using the204Hg(α, pn)-reaction andα-particles of energies 39–55 MeV, we have found an isomeric 3.6 min 12? state in206Tl at 2,642.9 keV which has the two-hole configurationπh 11 2/?1 vi 13 2/?1 The 12? state decays mainly by anE5 transition of energy 1,021.4 keV to a 7+ state at 1,621.5 keV whose main configuration isπs 1 2/?1 vi 13 2/?1 There is, in addition, evidence for a weak 565 keVM 4 branch to an 8+ state at 2,078 keV whose main configuration should beπh 11 2/?1 vf 5 2/?1 . The 7+ state decays by a stretched cascade ofγ-rays to states of the following values ofJ π and excitation energy: 5 ? + , 1,405.4 keV; 4?, 952.1 keV; 2?, 265.8 keV and 0?, 0 keV. The main configurations of these states areπh 11 2/?1 vp 1 2/?1 ,πd 3 2/?1 vf 5 2/?1 ,πd 3 2/?1 vp 1 2/?1 andπs 1 2/?1 vp 1 2/?1 respectively. From the nuclear masses of208Pb,207Pb,207Tl, and206Tl and the experimental excitation energies it is possible to obtain the proton hole-neutron hole interaction in206Tl. This interaction is compared with the calculations of Kuo and Herling and the discrepancies are discussed. The 12?→8+ M4 transition rate is reduced because of destructive interference between the protonh 11/2d 3/2 and the neutroni 13/2f 5/2 contributions. The magnitude of the reduction is accurately reproduced by the wave functions of Kuo and Herling. The 12?→7+ E5 transition rate is about twice as large as the single-holeπh 11 2/?1 πs 1 2/?1 transition rate. This deviation is fully explained by the configuration admixtures in the 7+ state, given by Kuo and Herling.  相似文献   

14.
Using the Mössbauer technique electric hyperfine interactions of the first excited non-rotational states at 64 keV in157Gd and at 86.5 keV in155Gd have been determined in GdF3 and GdCl3· 6H2O. For the ratio of quadrupolmoments the ratiosQ 64 157 /Q g 157 =1.74±0.04,Q 86.5 155 /Q g 157 =?0.07 ± 0.21 andQ g 155 /Q g 157 =0.78 ± 0.06 were found. In addition isomer shifts were observed from which a ratio δ〈r2 64 157 /δ〈r2 86.5 155 =?2.6±0.15 can be inferred.  相似文献   

15.
The asymmetry between the spectra of leading and nonleading charmed mesons that was measured in Σ? A interactions at p L=340 GeV/c in the WA89 experiment is described within the Model of Quark-Gluon Strings (QGS model also known as QGSM) under the assumption that there is a fraction of charmed sea quark-antiquark pairs (intrinsic charm) in an interacting hyperon. It is shown that the asymmetries between D ?-and D +-meson spectra and between D s ? -and D s + -meson spectra can be approximated by QGSM curves obtained with the same string-fragmentation parameter, a 1=10, and the same intrinsic-charm fraction, $\delta _{c,\bar c} = 0.01$ , as those that were used in describing D s ? /D s + -meson asymmetry of π? A experiments in previous studies. The asymmetry between the spectra of Λc and $\bar \Lambda _c $ that was measured in Σ? A collisions at p L=600 GeV/c in the E781 experiment is also described within this scheme. The QGSM results are compared with the results of the calculations in the next-to-leading approximation of perturbative QCD that were performed by other authors.  相似文献   

16.
InclusiveK s 0 andK s 0 K s 0 production in \(\bar pp\) interactions at 3.0, 3.5, 4.0 and 4.5 GeV/c are studied. Cross sections ofK s 0 , K s 0 K s 0 andK (892) are presented for each incident momentum. The production ofK s 0 andK (892) through annihilation process is investigated. It is found that the annihilation process is dominant but decreases with incident momentum. The annihilation process is compared withe + e ? interactions. Remarkable similarity between them is found in the \({{x_0 = 2E(K_s^0 )} \mathord{\left/ {\vphantom {{x_0 = 2E(K_s^0 )} {\sqrt s }}} \right. \kern-0em} {\sqrt s }}\) distribution. Events with two detectedK s 0 's are analyzed. The result shows theK s 0 K s 0 pairs are produced in the central region of c.m. system and there is a clearS * signal in theK s 0 K s 0 effective mass distribution.  相似文献   

17.
In our systematic investigations on the hyperfine structure (hfs) of high lying metastable states in 3d-shell atoms we have found evidence for an extraordinary strong far configuration mixing effect on off-diagonal matrix elements between configurations. Using theABMR-LIRF method the hfs of (3d 2 4s 2)3 P 47Ti, (3d 3 4s 2)4 P 51V (3d 5 4s 2)4 G 55Mn and (3d 6 4s 2)3 H 57Fe has been measured. Values found for the effective radial parameters \(a^{k_s k_l } \) of the magnetic dipole interaction disagreed up to 300% with those known from hfs measurements of lower lying multiplets of the same configuration, even when intermediate coupling and electrostatically correlated second order hfs effects within each of the configurations are taken into account. We suggest that the main part of these discrepancies can be explained, if two-body core polarization is considered, which screens the ordinary one-body core polarization parametera 3d 10 . Preliminary values for the corresponding parameters are given.  相似文献   

18.
The HFS-splitting of the 2s-2p and 3d-2p transitions of muonic arsenic and 3d-2p transitions of copper have been measured with high resolution Ge-semiconductor detectors to determine the nuclear quadrupole moments. A coincidence measurement was performed to separate the 2s-2p transition from the background. The nuclear spectroscopic quadrupole moments were found to be:Q spec=0.314(6) b for 33 75 AsQ spec=0.220(15) b for 29 63 Cu. In addition, generalized Barrett moments were determined in a model-independent analysis of muonic transition energies.  相似文献   

19.
The hyperfine structure splitting of the 82 P 3/2 state of Rb85 and Rb87 has been investigated with optical double resonance. The following interaction constants have been obtained:A 8p 85 =1.99(2) MHz,B 8p 85 =1.98(12) MHzA 8p 87 =6.75(3) MHz,B 8p 87 =0.96(6) MHz. The lifetime of the 82 P 3/2 state is: τ=4.0(8) · 10?7 sec.  相似文献   

20.
Using the experimentally measured values ofx=A 2(0)/A 1(0) andy=V(0)/A 1(0) and the measured ratiosR st=Γ(D s + φl + ν l)/Γ(D ins + φπ +) andR h=Γ(D s + φρ +)/Γ(D s + φπ +), we present evidence for significant nonfactorization contribution in the decay amplitude forD s + φπ +. We analyze the role of nonfactorization inD s + φρ + and conclude that present data onR h are consistent with factorization inD s + φρ +. A measurement of polarization inD s + φρ + would greatly assist our analysis.  相似文献   

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