Showing papers on "Anomaly (physics) published in 1973"
TL;DR: In this article, the phonon dispersion relations for gold in the high-symmetry directions have been measured at room temperature by the coherent inelastic scattering of neutrons.
Abstract: The complete phonon dispersion relations for gold in the high-symmetry directions have been measured at room temperature by the coherent inelastic scattering of neutrons. It is found that the forces in gold are not homologous with the other noble metals, the frequencies of gold lying appreciably higher than those "scaled" from copper and silver. An analysis of the data in terms of different force-constant models reveals that a general tensor force is required for the first-neighbor interaction, whereas for neighbors beyond the first either general tensor or axially symmetric forces give an excellent fit to the data. The axially symmetric model alone does not adequately describe the data even when forces extending to ninth-nearest neighbors are included in the fit. In addition, simple screened-pseudopoential models were fit to the data and these results also indicate the need for the first-neighbor interaction to be general. Frequency distribution functions and related thermodynamic quantities were calculated from the various force-constant models. The Debye temperature ${\ensuremath{\Theta}}_{C}$ versus temperature curves obtained show an anomaly at low temperatures consistent with the ${\ensuremath{\Theta}}_{C}(T)$ obtained from specific-heat measurements. The relation between this anomaly and the character of the dispersion curves is given.
268 citations
TL;DR: The energy spectra of 162 Er and 168 Yb have been calculated using the Hartree-Fock-Bogoliubov theory and the self-consistent cranking model as discussed by the authors.
146 citations
TL;DR: In this paper, it was shown that the linear splitting in a magnetic field of the thermal anomaly observed recently in liquid at about 25 mK can be explained by postulating pairing in a state of odd relative angular momentum.
Abstract: It is shown that the linear splitting in a magnetic field of the thermal anomaly ($A$) observed recently in liquid ${\mathrm{He}}^{3}$ at about 25 mK can be explained by postulating pairing in a state of odd relative angular momentum Further structure is predicted, and implications of the theory and experiment are discussed
116 citations
TL;DR: In this paper, a double-crystal X-ray diffraction technique has been applied to the lattice constant measurement of SrTiO 3 in the temperature range 17 to 300 K.
100 citations
TL;DR: In this paper, the superparamagnetic relaxation time for spherical particles with cubic magnetocrystalline anistropy, whose easy axis is either [100] or [111] in zero applied field, was calculated.
Abstract: The superparamagnetic relaxation time is calculated for spherical particles with cubic magnetocrystalline anistropy, whose easy axis is either [100] or [111] in zero applied field. Results are reported for relatively small particles only, in which no anomaly is found. It is concluded that the experimentally observed anomaly in this size region must be due to incoherent magnetization reversals.
63 citations
TL;DR: The absence of radiative corrections to the Schwinger-Bell-Jackiw-Adler anomaly of the axial-vector-current Ward-Takahashi identity is demonstrated using normal-product methods.
Abstract: The absence of radiative corrections to the Schwinger-Bell-Jackiw-Adler anomaly of the axial-vector-current Ward-Takahashi identity is demonstrated using normal-product methods.
29 citations
TL;DR: In this article, the NMR frequency shifts for 31 P and 75 As in the compounds CeP and CeAs have been measured between the Neel point and 200°K, and the ratio of resonance shift to bulk magnetic susceptibility, expected to be independent of temperature, was found to increase with increasing temperature by approximately a factor of two.
27 citations
CERN1
TL;DR: The absence of strong interaction corrections to the axial anomaly in the σ model is proved in a cut-off independent way using Zimmermann's normal product algorithm.
Abstract: The absence of strong interaction corrections to the axial anomaly in the σ model is proved in a cut-off independent way using Zimmermann's normal product algorithm.
26 citations
TL;DR: In this paper, the contribution of light-by-light scattering subgraphs to the 6th order anomaly is recomputed, and the result is: aeγ−γ = (α3/π3)(0.366 ± 0.010).
22 citations
01 Jan 1973
TL;DR: In this paper, the two-body Coulomb force is replaced by the effective one-body force which is essentially the charge monopole operator, and the mixing effects of this operator are evaluated in terms of two sum rules of the operator.
Abstract: We set up a systematic approach to Coulomb mixing based on two simplifications: (1) the two-body Coulomb force is replaced by the effective one-body force which is essentially the charge monopole operator, (2) the mixing effects of this operator are evaluated in terms of two sum rules of this operator. These yield the mean-square amplitude and mean energy of the charge monopole mode of oscillation. Contributions of different admixed isospins can be separated. Evaluations are made with two models, the shell model and an improved model taking two-body correlations into account. For the latter, we find it very useful to proceed by analogy with the well-known charge dipole problem. The bulk of the article is concerned with comparing experiment and theory for the different observed aspects of Coulomb mixing. An analysis is also made of the most complete calculation available of an analog state. Generally experiment and theory are in accord, especially when the correlated model is used. When sum-rule evaluations are made with the shell model, no explanation is found of the Nolen–Schiffer anomaly; rather the opposite, viz., a large second-order shift (-2 MeV for 208Pb) is found which reduces the estimated Coulomb displacement. However, when correlation effects are included, not only is this second-order shift less, but one finds evidence that correlations may increase the first-order term. These two effects are in the right direction but probably insufficient in magnitude to explain the anomaly.
21 citations
TL;DR: In this article, the temperature-density phase anomaly is discussed on the basis of a quasi-three-dimensional model in which the thermosphere dynamics (including energy advection and diffusion associated with wind circulation) is considered in a self consistent form.
Abstract: The temperature-density phase anomaly is discussed on the basis of a quasi-three-dimensional model in which the thermosphere dynamics (including energy advection and diffusion associated with wind circulation) is considered in a self consistent form. Included in this analysis are the first three harmonics with nonlinear coupling between diurnal and semi-diurnal tides.
01 Nov 1973
TL;DR: In this paper, the authors measured the coefficient of thermal expansion, α, above the T c of tri-glycine-sulfate (TGS) and demonstrated the presence of a logarithmic anomaly in α, in agreement with the generalized Pippard relations between the previously measured specific heat and α.
TL;DR: A residual negative free-air and Bouguer anomaly of at least 80 milligals, superimposed on a broader high, occurs over the Gal�pagos Islands, suggesting a low-density mass in the crust or upper mantle must underlie the archipelago.
Abstract: A residual negative free-air and Bouguer anomaly of at least 80 milligals, superimposed on a broader high, occurs over the Galapagos Islands The axis of the anomaly trends roughly east and plunges eastward. Thus, a low-density mass in the crust or upper mantle must underlie the archipelago. This anomaly may be caused by thermal expansion over a crust-mantle " hot spot".
TL;DR: In this article, the Callan-Symanzik equations were used to study the short-distance behavior of the gauge-invariant axial-vector current in quantum electrodynamics.
Abstract: Using the Callan-Symanzik equations as a tool to study the short-distance behavior of the gauge-invariant axial-vector current in quantum electrodynamics, we conclude that as a consequence of Ward identities the axial-vector current is required to scale noncanonically. The Wilson-Crewther calculation of the anomaly cannot be carried out, although its use is legitimate in phenomenological applications treating electromagnetism to lowest order.
TL;DR: In this paper, the specific heat anomaly of niobium was shown to be caused by hydrogen impurity, and substituting deuterium for hydrogen produces a significant change in the temperature dependence of the anomaly.
TL;DR: In this paper, it was shown that the giant Kohn phonon anomaly characteristic of a one-dimensional metal may also be found in a Peierls semiconductor, and a simple model reflecting roughly the LA-phonon dispersion of K 2 Pt(CN) 4 Br 0.3 · 3H 2 O has been used to get numerical results.
TL;DR: In this paper, the authors used a newly calculated conduction-electron density of states (DESS) to explain the Van Hove singularity in the electron energy bands of iron.
Abstract: The properties of a particular Van Hove singularity in the electron energy bands of iron have been studied theoretically. Its presence in iron bands may explain the anomaly in the isomer shift of iron near ${T}_{c}$ discovered by Preston, Hanna, and Heberle some time ago. To date, no satisfactory theory has been given for this anomaly. The explanation offered here uses a newly calculated conduction-electron density of states and depends on a small (\ensuremath{\sim}10 mRy) band shift. In addition, the effects of the singularity on other electronic properties of iron are discussed.
TL;DR: In this paper, the Kaula rule of 10−5/l2 was examined considering anomaly degree variances obtained from satellite gravity field computations, anomaly block variances in 10°, 5°, 2°, 1° and 5′ blocks, and the point anomaly variance as estimated from terrestrial gravity information.
Abstract: The Kaula rule of thumb (10−5/l2) that describes the behavior of gravitational potential coefficients has been examined considering anomaly degree variances obtained from satellite gravity field computations, anomaly block variances in 10°, 5°, 2°, 1°, and 5′ blocks, and the point anomaly variance as estimated from terrestrial gravity information. Other models were considered in an attempt to find a model that would best fit the data in a weighted least squares sense. Of the models tested, the following was considered best for describing the anomaly degree variance: σl2(Δg) = C(l − 1)/[(l − 2) (l + D + ∈l2)] with C = 246.5556, D = 12.6755, and ∈ = 0.000657. This equation yields anomaly degree variances that fit the observed anomaly degree variances and anomaly block variances better than those implied by the Kaula rule and whose sum converges to the point anomaly variance of approximately 1206 mgals2, as opposed to a divergent summation of the anomaly degree variances implied by the Kaula rule.
TL;DR: In this paper, a simple scaling argument is given to estimate the anomaly in surface tension at the λ-point of liquid helium and the result agrees with an earlier one of Sobyanin, based on the Ginzburg-Pitaevskii equation.
Abstract: A simple scaling argument is given to estimate the anomaly in surface tension at the λ-point of liquid helium. The result agrees with an earlier one of Sobyanin, based on the Ginzburg-Pitaevskii equation.
TL;DR: In this article, the speed of sound in pure water between 0° and 10°C was measured and it was shown that there is no anomaly larger than 2 ppm. But this was not the case in the case of pure water.
Abstract: Over 1000 relative measurements of the speed of sound in pure water between 0° and 10°C contribute nothing additional to the earlier indication [V. A. Del Grosso and C. W. Mader, J. Acoust. Soc. Amer. 52, 1442–1446 (1972)] that there is no anomaly larger than 2 ppm.
31 Aug 1973
TL;DR: In this paper, a scheme for the detection of the passage of ships and other permeable objects using stationary component magnetometers is described, which requires as complete a cancellation of the natural geomagnetic micropulsation noise as is possible in the frequency range from 0.001 to 1 Hz.
Abstract: : A scheme for the detection of the passage of ships and other permeable objects which uses stationary component magnetometers is described. The system requires as complete a cancellation of the natural geomagnetic micropulsation noise as is possible in the frequency range from 0.001 to 1 Hz. A simple method for detecting the magnetic anomaly produced by a passing ship is to form the difference between parallel components of the magnetic field variations at each end of a baseline several miles in length. The geomagnetic micropulsation noise tends to cancel, but the target anomaly is more localized and causes each magnetic sensor to operate almost independently for the target detection. However, in many locations the variation in local geology along the baseline introduces a 'geology filter' which must be removed by more elaborate measurement and computation. (Modified author abstract)
01 Jan 1973
TL;DR: One of the less obvious criteria of adequacy that any satisfactory analysis of confirmation must meet is the requirement that if such an analysis purports to explicate the concept of confirmation or support it must be capable of explicating or elucidating the idea of what scientists call an ‘anomaly’.
Abstract: In the present paper I shall discuss one of the less obvious criteria of adequacy that any satisfactory analysis of confirmation must meet, viz. the requirement that if such an analysis purports to explicate the concept of confirmation or support which is in common use in natural science it must be capable of explicating or elucidating the concept of what scientists call an ‘anomaly’.
TL;DR: In this article, the susceptibility of a type of KCuF3 was measured on a single crystal sample obtained from the melt and an anisotropic temperature dependence and the anomaly at the TN were observed.