共查询到20条相似文献,搜索用时 31 毫秒
1.
H.E. Rorschach 《Annals of Physics》1976,98(1):70-86
A discussion of the shielding of a charged particle in a current-carrying conductor is given that is based on the linearized Thomas-Fermi approximation. An expression for the force on a particle of charge q is obtained from which the value of the electric field Ec in the conductor may be found: It is shown that the force on the particle has the form to second order in the charge q, where E0 is the electric field at large distances from q, e is the charge of the carrier, and γ is a material-dependent constant. The shielding correction has the character of a “wind-force,” and the electric field in the conductor is given by Ec = E0. 相似文献
2.
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
3.
J.M. Blackledge 《Physics letters. A》1985,110(4):188-194
Exact inverse solutions to the integral equation , where g(r|rj, k); j = 0 or s is the free space Green function, are derived in plane and cylindrical coordinates for fixed ω. These solutions allow an inelastic scattering potential f(r, ω) which is of compact support r ? 3 to be recovered from scattering data collected over the surfaces of a plane and cylinder respectively. 相似文献
4.
S. Gjesdal G. Presser P. Steffen J. Steinberger F. Vannucci H. Wahl F. Eisele H. Filthuth V. Lüth G. Zech K. Kleinknecht 《Physics letters. [Part B]》1974,52(1):119-121
The phase φ+? is evaluated on the basis of measurements of the KS-KL interference in the π+π? decay mode and the mass difference Δm, both reported previously by this group. The result is: φ+? = 45.9° ± 1.6°. This, together with previous results on and the charge asymmetry δ in leptonic decay, is compared with the prediction of the superweak model, with good agreement.Finally the result is used to find, on the basis of unitarity, a new upper limit on CP violation in the decay K0 → 3π0. This limit is |η000|2? 0.21. 相似文献
5.
J.G. Rushbrooke R.E. Ansorge C.P. Bust J.R. Carter W.W. Neale C. Moore R. Raja L. Voyvodic R.J. Walker W. Morris B.Y. Oh D.L. Parker G.A. Smith J. Whitmore 《Physics letters. [Part B]》1975,59(3):303-307
New 100 GeV/cp data are used to find moments of the difference between the p and pp topological cross sections. The mean multiplicity for annihilations at 100 GeV/c is estimated to be 9.06 ± 0.56, and the value of the quantity 〈n〉/D to be 2.75 ± 0.33. It is shown that appears at 100 GeV/c to have acquired an asymptotic form, Rn = s?αβn, with α and β constant. 相似文献
6.
The cyclotron resonance of inversion-layer electrons on (100)p-type Si is found to depend sensitively on an externally applied compressive stress. At low temperatures (T ? 10 K) we observe a considerable increase of the cyclotron mass m1c with stress S along the [001] direction. The effect is most strongly observed at low electron densities ns. For and ns~2 × 1011cm-2 we obtain instead of the expected 0.2m0. Along with this change of a strong narrowing of the resonance is noted. Raising the temperature gives an additional ns- dependent increase of . 相似文献
7.
J. Leotin R. Barbaste S. Askenazy M.S. Skolnick R.A. Stradling J. Tuchendler 《Solid State Communications》1974,15(4):693-697
The first observation of cyclotron resonance in p-type InP is reported. The holes were thermally excited at 110 K and the resonance was observed at 337μm wavelength (HCN laser) using a pulsed magnetic field of 0–350 kG. The effective masses of the light and heavy holes in the 〈111〉 direction were found to be , and in the 〈100〉 direction , . We obtain an estimate of the Dresselhaus parameters A = ?5.04, |B| = 3.12, C2 = 6.57. We also report the effective masses for p-type GaP in the 〈111〉 direction as , . 相似文献
8.
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
9.
B.L. Ioffe 《Nuclear Physics B》1981,188(2):317-341
The polarization operator of quark currents with baryon quantum numbers is considered in quantum chromodynamics. The non-zero mean vacuum values of the field operator products are taken into account. The sum rules are obtained assuming that in the virtuality region ~1 GeV, among the mean vacuum values violating the chiral invariance, the most important is . Saturating these sum rules by the lowest baryonic states one is able to calculate the masses of the isobar Δ and nucleon N, MΔ = 1.4 GeV, MN = 1 GeV, up to 15% through the known value . The mass splitting in the baryonic decuplet is calculated in first order in the current strange quark mass ms = 150 MeV. Certain results for other baryonic resonances have also been obtained. 相似文献
10.
By continuing the 2H(, p)3H, Ed = 13.0 MeV tensor polarizations to the forward and backward transfer poles it was possible to determine the corresponding values for the deuteron (0.0268 ± 0.0007) and triton (0.048 ± 0.007). 相似文献
11.
W.K. Theumann 《Physica A》1975,83(1):85-120
The two-point correlation function ? (q, ξ) is calculated in the critical region of momentum space q in terms of a suitable correlation lenght ξ, by means of perturbation expansion to order 1/n, for an n-vector system with long-range interactions decaying as , for , where a is the spacing on a d-dimensional lattice, σ < d < 2σ and 0 < σ ? 2 ? ηSR. The calculations are done in zero field for T ? Tc. Explicit expansions for long-range propagators are developed for and for the neighborhood of σ ? 2 ? ηSR, in terms of which a universal, cut-off independent scaling function is obtained over the whole range of , and it is shown that the amplitude of the correlation-length dependence of the susceptibility becomes a universal parameter. Both the exponents and the coefficients of the expansion for fixed q as are calculated explicitly. The former are shown to require the validity of the operator-product expansion and explicit logarithmic correction terms are obtained for . For these and other dimensionalities, the coefficients are shown to be finite functions of d and σ. The correction to the Ornstein-Zernike form is given explicitly, with non-integer powers of x that have finite coefficients. 相似文献
12.
Spin lattice relaxation T1 of naturally abundant 13C nuclei in squaric acid was measured close to the antiferroelectric-paraelectric phase transition temperature Tc = 373 K. A rapid increase in is observed close to Tc coming from above, which follows the power law where . This behaviour is explained on the basis of the two-dimensional character of the fluctuations. 相似文献
13.
Excitation functions of the capture reaction 12C(p, γ0)13N have been obtained at θγ = 0° and 90° and Ep = 150–2500 keV. The results can be explained if a direct radiative capture process, E1(s and d → p), to the ground state in 13N is included in the analysis in addition to the two well-known resonances in this beam energy range and 1699 . The direct capture component is enhanced through interference effects with the two resonance amplitudes. From the observed direct capture cross section, a spectroscopic factor of C2S(l = 1) = 0.49 ± 0.15 has been deduced for the ground state in 13N. Excitation functions for the reaction have been obtained at θγ = 0° and 90° and Ep = 610–2700 keV. Away from the 1699 keV resonance the capture γ-ray yield is dominated by the direct capture process E1 (p → s) to the unbound state. Above Ep = 1 MeV, the observed excitation functions are well reproduced by the direct capture theory to unbound states (bremsstrahlung theory). Below Ep = 1 MeV, i.e., Ep → 457 keV, the theory diverges in contrast to observation. This discrepancy is well known in bremsstrahlung theory as the “infrared problem”. From the observed direct capture cross sections at , a spectroscopic factor of C2S(l = 0) = 1.02 ± 0.15 has been found for the unbound state. A search for direct capture transitions to the and unbound states resulted in upper limits of C2S(l = 1) ≦ 0.5 and C2S(l = 2) ? 1.0, respectively. The results are compared with available stripping data as well as shell-model calculations. The astrophysical aspect of the 12C(p, γ0)13N reaction also is discussed. 相似文献
14.
The γ-decay of 26 resonances in the reaction 60Ni(p, γ)61Cu in the range Ep = 3690–3790 keV has been investigated. The isobaric analogue state (IAS) corresponding to the parent state at in 61Mi has been resolved into several fine structure components. The absolute strength for the transition to the antianalogue state is found to be Γγ = 0.24 ± 0.07 W.u. The measured M1 strength distribution for the decay of the . IAS is compared to theoretical predictions. 相似文献
15.
C. Bruneton J. Bystricky G. Cozzika J. Deregel A. Derevschikov Y. Ducros A. Gaidot Yu. Kazarinov M. Kazarinov V. Kanavets B. Khatchaturov F. Lehar A. De Lesquen Yu. Matulenko J.P. Merlo A. Mecshanin S. Miyazhita J. Movchet V. Solovyanov 《Physics letters. [Part B]》1973,44(5):471-473
We report our first measurements of the polarization in the elastic scattering of negative pions from polarized protons at an incident pion momentum of 40 GeV/c. The momentum-transfer region covered was 0.08 < |t| < 1.3 (GeV/c)2. The angular distribution of the polarization exhibits a first minimum of ~ ? 5% and the well-known zero around t ≈ ? 0.6 (GeV/c)2. The energy variation of the first minimum (at around t = ? 0.2) may be expressed in a simple form, . 相似文献
16.
J. Banaigs J. Berger L. Goldzahl T. Risser L. Vu-Hai M. Cottereau C. Le Brun 《Physics letters. [Part B]》1973,45(4):394-398
The reactions d + p → τ + π0 and d + p → τ + η0 were studied using the missing-mass method for incident deuteron momenta between 2.8 and . The angular distributions show a peak in the forward direction () and are flat in the backward direction. The differential cross sections at for both reactions show a maximum for total center-of-mass energies near 3.46 GeV. 相似文献
17.
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; , , , |q5| = 16.005, and |q6| = 8.456 MHz. 相似文献
18.
The magnetic hyperfine splitting νM = |gμNBHF/h| of ; 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
19.
The magnetic hyperfine splitting vM=|gμNBHF/h| of 196mAu (jπ=12?; configuration ¦(π(; 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 and isomeric states in the neighbouring odd Pt, Au and Hg nuclei the structure of the 12? state is discussed. 相似文献
20.
A. Apostolakis R. Casali C. Caso Y. Goldschmidt-clermont L. Pape J.P. Porte A. Stergiou B. Tallini G. Vassiliadis H. Wenninger G. Grard V.P. Henri P. Herquet J. Kesteman S. Banerjee K.W.J. Barnham R. Beuselinck I. Butterworth A. Jacholkowska 《Physics letters. [Part B]》1977,66(2):185-190
We report the evidence for a narrow charged peak (5.5 s.d.), which we suggest calling the I, in the 6-prong-V0 topology of p interactions at 12 GeV/c. The mass, widht and the product of cross section σI times the branching ratio BR into the final state (Ksoτ±τ+τ? are found to be: , , σI·BR≈20 μbarn 相似文献