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Journal Article

New finite model in d = 2

25 Jun 1984-Jetp Letters-Vol. 39, pp 573
TL;DR: In this article, an N = 4 supersymmetry model for scalars and spinors in dimensionality two has been derived through a dimensional reduction of an n = 2 real chiral superfield to d = 4.
Abstract: An N = 4 supersymmetry model for scalars and spinors in dimensionality two has been derived through a dimensional reduction of an N = 2 real chiral superfield to d = 4. All the ultraviolet divergences cancel out in all orders of perturbation theory.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, the two-loop counterterms for the nonlinear sigma model on a general scalar manifold with torsion are calculated using the background field method, showing how the purely bosonic results carry over completely in superspace.

28 citations

Book ChapterDOI
TL;DR: In this paper, the authors used synchrotron radiation (SR) for the excitation of a Mossbauer transition, and the results demonstrated the effectiveness of using SR in yet another promising area of research.
Abstract: Although the first proposal to use synchrotron radiation (SR) for the excitation of a Mossbauer transition was made by S.L. Ruby in 1974 [1], only in 1983 was a paper published [2] on successful Mossbauer investigation with the use of SR, carried out in the Soviet Union at the VEPP-3 storage ring in Novosibirsk (Institute of Nuclear Physics, Siberian branch of the Academy of Sciences of the USSR). In 1985 a similar investigation [3,4] was carried out in the Federal Republic of Germany at the SR source in Hamburg (HASYLAB). These investigations demonstrated the effectiveness of using SR in yet another promising area of research and they were milestones in a number of Mossbauer investigations with SR [4–6]. The essence of this work is that they have succeeded in extracting (filtering) out of the continuous SR spectrum an extremely highly monochromatized and tightly collimated beam of gamma radiation of rather high intensity. The physical principal underlying the filtration process is the properties of Mossbauer diffraction (i.e., discussed in Chapt. 3 as the diffraction of radiation when it is scattered resonantly by the nuclei of the crystal through the Mossbauer transition). This diffraction makes it possible to separate spatially and energetically the radiation that has undergone coherent resonance scattering. The degree of monochromatization ΔE/E and the energy E of the beam are determined by the corresponding parameters of Fe57 Mossbauer transition used in both experiments, i.e., E = 14.4 keV and ΔE/E →~ 3.10−13.

9 citations

Journal ArticleDOI
TL;DR: 'Forbidden'
Abstract: 'Forbidden' Bragg reflections of iron orthoborate Fe3BO6 were studied theoretically and experimentally in the vicinity of the iron K edge. Their energy spectra are explained as resulting from the interference of x-rays scattered from two inequivalent crystallographic sites occupied by iron ions. This particular structure property gives rise to complex azimuthal dependences of the reflection intensities in the pre-edge region as they result from the interplay of site specific dipole–quadrupole and quadrupole–quadrupole resonant scattering. Also evidenced is an anisotropic character of the absorption spectrum. Self-absorption correction to the diffraction data, as well as possible contributions of thermal vibrations and magnetic order, are discussed. Particular care is given to extracting clean spectra from the data, and it is demonstrated that excellent results can be obtained even from measurements that appear corrupted by several effects such as poor crystal quality and multiple scattering.

7 citations

Book ChapterDOI
20 Jan 2021
TL;DR: In the last few decades, nuclear resonance scattering of synchrotron radiation has developed from a dream to an advanced suite of powerful methods, gathering a wide range of applications from general relativity to nanoscience as mentioned in this paper.
Abstract: In few decades, Nuclear Resonance Scattering of synchrotron radiation developed from a dream to an advanced suite of powerful methods, gathering a wide range of applications from general relativity to nanoscience, combining unprecedented properties of nuclear resonance and synchrotron light, and expanding studies to multiply extreme conditions. This article reviews fundamentals of nuclear resonance physics and properties of synchrotron radiation, provides a short historical overview of the fascinating development, major techniques and instrumentation of the method, and gives a brief snapshot of modern applications and yet coming opportunities.

4 citations

Journal ArticleDOI
TL;DR: In this article, a method of resonant filtering has been used to preserve the unique properties of synchrotron radiation which can now be combined with the high energy resolution of Mossbauer experiments.
Abstract: Monochromatization of synchrotron radiation by nuclear Bragg diffraction in YIG has been obtained. This method of resonant filtering preserves the unique properties of synchrotron radiation which can now be combined with the high energy resolution of Mossbauer experiments.

2 citations