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1.
The microwave spectrum of MnO3F has been remeasured and several corrections and new results have been obtained: B0 = 4129.141 MHz, DJ = 1.12 kHz, DJK = 1.87 kHz; α3B = 8.622, α5B = ? 11.994, α6B = 6.042, |q5| = 16.005, and |q6| = 8.456 MHz.  相似文献   

2.
The magnetic hyperfine splitting νM = |NBHF/h| of 193mAu (jπ = 112?, E = 290 keV; T12 = 3.9 s) as a dilute impurity in Ni has been measured with nuclear magnetic resonance on oriented nuclei as 226.4(2) MHz. With the known hyperfine field BHF = ?264.4(3.9) kG corrected for hyperfine anomalies the g-factor and magnetic moment of 193mAu are deduced to be |g| = 1.123(17) and |μ| = 6.18(9) μN.  相似文献   

3.
E. Hagn  E. Zech 《Nuclear Physics A》1982,373(2):256-266
The magnetic hyperfine splitting vM=|gμNBHF/h| of 196mAu (jπ=12?; configuration ¦(π112(v132+)〉12?; T12 = 9.7 h) as dilute impurity in Ni has been determined with nuclear magnetic resonance on oriented nuclei as 96.0(2) MHz. With the known hyperfine field BHF = ?264.4(3.9) kG corrected for hyperfine anomalies the g-factor and magnetic moment of 196mAu are deduced to be |g| = 0.476(7) and |μ| = 5.72(8) μN. Taking into account the known magnetic properties of π12? and v132+ isomeric states in the neighbouring odd Pt, Au and Hg nuclei the structure of the 12? state is discussed.  相似文献   

4.
R. Eder  E. Hagn  E. Zech 《Nuclear Physics A》1984,413(2):247-254
The magnetic hyperfine splitting νM = |NBHF/h| of 175Ta (Jπ = 72+; T12 = 10.5 h) in Fe has been measured with the technique of nuclear magnetic resonance on oriented nuclei as 320.4(1) MHz. With the known hyperfine field BHF(TaFe) = ?648(13)kG the magnetic moment of the 72+[404] ground state of 175Ta is deduced to be ¦μ¦ = 2.27(5)μN.  相似文献   

5.
6.
The reactions 12C(d, α)10B, 18O(d, α)16N and34S(d, α)32P have been investigated at Ed = 52 MeV. Vector analyzing powers as large as ¦iT11¦=0.85 are observed. They exhibit patterns characteristic for final spins I = |L?1|, L or L + 1 and provide spin determinations at least for states of unique L-transfer. Local, zero-range DWBA calculations assuming deuteron-cluster pick-up reproduce qualitatively the observed effects. The method has been tested for states of known spin, and then has been applied to determine spins of states with stretched coupling in 16N: Jπ = 3+(3.96 MeV), 4?(6.17 MeV) and in 32P: Jπ = 5+(4.75 MeV). There is strong evidence for further 5+ states in 32P at 6.43, 7.96, 8.09 and 8.54 MeV.  相似文献   

7.
The branching ratios are calculated for 11ΛB decay to the 11C ground and excited states below 8 MeV for two possible spin values of 11ΛB. It is found that the decay rate to the 11C state at E = 6.48 MeV is comparable in magnitude to that leading to the 11C ground state if J(11ΛB) = 52 is assumed. This result, unlike the branching ratios calculated for the J(11ΛB) = 72 case, is in accord with experiment and lends support to the assumption that J = 52 holds for 11ΛB. The necessity of the reinterpretation of some of the so-called 13ΛC events in terms of 11ΛB → π? + 11C1 is indicated.  相似文献   

8.
The diffusion constant (D) and the spin depolarisation rate (λS) of the positive muon in the ferromagnetic b.c.c. lattices such as Fe have been calculated on the basis of the small polaron (SP) model with particular attention to the hopping and the coherent motions. They have been obtained in the forms: D=d2wD6 and λS=2μH2d3wS, where d is a jump length, and Hd is a magnitude of internal dipolar field. At high temperatures, the activated-type hopping motion gives a dominant contribution to wD, and wS coincides with wD. With decreasing temperature, wD turns to be increasing owing to the coherent motion. Whereas wS deviates from wD, after passing the minimum, to have a maximum, and then decreases in inverse proportion to a lifetime (B) of the SP band states. Because of the cell periodicity of the internal fields, the spin in an SP band state feels a definite magnetic field corresponding to the state, and sees various fields if scattered to other states. These scattering processes succeeding in a time shorter than (γμHd)-1 result in the motional narrowing of the spectra, with λS ? γ2μHdB.  相似文献   

9.
It is rigorously shown that the superconducting transition temperature of any material for which the Eliashberg theory is valid must satisfy kBTc ? 0.2309 A, where A is the area under its electron-phonon spectral function α2F(ω). This relation is a least upper bound, not just an upper bound, in the sense that there is an optimal situation in which the equality holds. This occurs when the Coulomb pseudopotential parameter μ1 is zero and the spectral function is the Einstein spectrum (ω ? 1.750 A). These results are generalized in an approximate, but sufficiently accurate, way to the case μ1 ≠ 0 to obtain the more useful least upper bound kBTc ? c(μ1) A and the corresponding optimal spectrum Aδ[ω ? d(μ1)A]. Numerical results for the functions c(μ1) and d1) are presented for 0 ? μ1 ? 0.20. It is shown that the Tc's of many materials (including Nb3Sn), for which experimental values of A and μ1 are available, do not lie very far below the upper bound.  相似文献   

10.
For the S = 12 XY model at T = 0 four susceptibilities have been calculated exactly on a sequence of finite square lattices and extrapolated to the infinite square lattice. For the ferromagnet χzz = 0 while χxxN2.9; for the antiferromagnet JχxxN(gμB)2 = 0.025 ± 0.002 and JχxxN(gμB)2 = 0.13 ± 0.03.  相似文献   

11.
The fine structures of the (ν1 + ν2) and (ν2 + ν3) combination bands of ozone in the 5.7-μm region have been recorded and analyzed. The two vibrational states are coupled through Coriolis and second-order distortion terms. The interaction has been treated by the numerical diagonalization of the secular determinant for the two coupled states. With the centrifugal distortion parameters fixed to the ground state values, the following constants have been obtained: ν1 + ν2 = 1796.266, A110 = 3.6104, B110 = 0.44145, C1110 = 0.39029, ν2 + ν3 = 1726.526, A011 = 3.5537, B011 = 0.43982, C1011 = 0.38844, Y13 = ?0.466, and X13 = ?0.010 cm?1. In addition, the following anharmonic constants have been obtained: x12 = ?7.821 and x23 = ?16.494 cm?1. The value of the dipole moment ratio, R = 〈011|μz|0〉〈110|μx|0〉, is 1.30 ± 0.10.  相似文献   

12.
Reflectance spectra were measured on ZnTe in magnetic fields up to 18 T for B ? [100] and B ? [110]. The experiments yield renormalized valence band parameters γ12 = 0.83 ± 0.08 and γ13 = 1.30 ± 0.12, corresponding to bare parameters γ2 = 0.95 ± 0.09 and γ3 = 1.48 ± 0.14. From the free exciton Rydberg energy R10 = 12.8 meV we derive a reduced exciton polaron mass m0 0.080 ± 0.005 and a bare reduced mass m0 0.074 ± 0.005, corresponding to γ11 = 3.9 ± 0.7 and γ1 = 4.4 ± 0.7 for an electron effective polaron mass m1e = 0.116 m0. We further calculate the exciton diamagnetic shift rate according to existing low-field theories modified by a variational calculation taking into account polaron effects and valid up to γ ? 1. The difference between experiment and theory is 10% and the agreement is considered satisfactory.  相似文献   

13.
The hard photon emission in e+e?μ+μ?γ is investigated to order α3. Formulas for a number of distributions are obtained, when neglecting terms of order (me/?)2 and (mμ/?)2. Both charge-even and charge-odd contributions are calculated. The total contribution to the charge asymmetry parameter
? = [dσ(θ)dOμ+?dOσ(π?θ)dOμ+][dσ(θ)dOμ++dσ(π ? σ)dOμ+]
does not exceed 5% for the c.m.s. energy 2? = 3 GeV.  相似文献   

14.
We have obtained a least upper bound, kBTc ? c(μ1, t)A, on the critical temperature Tc of an isotropic superconductor with paramagnetic impurities described by the scattering matrix t for fixed values of μ1. We have also obtained the corresponding optimal spectrum α2F(m) = Aδ[ω?d(μ1, A]. The numerical results for the functions c(μ1, t) and d(μ1, t) are presented for α1 = 0.1 and 0.16 in the form of universal curves representing c(μ1, t) and d(μ1, t) as functions of the reduced impurity concentration t = t/A. We have also established an upper limit to the reduced critical concentration tcrit for an arbitrary shape of α2F(ω)1.  相似文献   

15.
Quark masses     
In quark gluon theory with very small bare masses, -ψMψ, spontaneous breakdown of chiral symmetry generates sizable masses Mu, Md, Ms, … We find (Mu + Md) /2 ≈ mp/ √6 ≈ 312 MeV, and Ms ≈ 432 MeV. Scalar densities have well determined non-zero vaccum expectations 〈0|ua|0〉 ≡ 〈0|ψ(x) (λa/2)ψ(x)/0〉 ≈ ?π2Ma, i.e〈0? uo/vb0〉 ≈ 8 × 10?3 (GeV)3 at an SU(3) breaking of the vacuum c′ ≡ 〈0|u8|〉/〈0|uo|0〉 ≈ ? 16%  相似文献   

16.
The massless electromagnetic Yang-Mills field is explicitly constructed as a linear combination EV3μ + (13) EV8μ of 16 gauge fields of the chiral SU(3) × SU(3) group within the framework of the plasmon generating mechanism [1]. The remaining 15 gauge fields acquire a mass through the non-zero vacuum expectation values of the auxiliary scalar multiplet which transforms according to the (8,8) representation of the gauge group. The tadpoles with non-zero hypercharge which are required for the existence of the only massless electromagnetic potential Aμ are due to the natural mixing of charged weak currents with ΔS = 0 and ΔS = 1. The relevance of this phenomenon to the Cabibbo angle is briefly discussed. Also presented is a theorem concerning an admissible form of the zero-order mass term of gauge fields when the canonical number is unknown.  相似文献   

17.
18.
We consider a neutrino field with geodesic rays in interaction with a gravitational field admitting a Killing vector field nμ. It is found that for solutions of the Einstein-Weyl field equations the neutrino field ξA and the neutrino flux vector lμ are restricted by the equations: LnξA = ?12is ξA and Lnlμ = 0, whereas s is a real constant. In the case of pure radiation neutrino fields these equations become: LξA = case12(p ? is)ξA, Lnlμ = plμ, where p and s are in general real functions of the coordinates.  相似文献   

19.
20.
It is shown that for spinorial charges Q(L))α (α = 1, 2, L = 1, …, S) satisfying the commutation relations
{Q(L)α, Q(M)β} = εαβaLMQ,
{Q(L)α, Q(M)+β} = cσμαβPμδLM,
[Q(L))α, Pμ] = 0,
where Q is a scalar charge commuting with the spinor charges as well aswith the energy- momentum vector Pμ, there can exist several different multiplets for free massive scalar and spinor fields.  相似文献   

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