1,542 research outputs found

    X-radiation of the moon and Roentgen cosmic background according to data of AMS ''Luna-12''

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    Satellite measurements of lunar soft X radiation, and Roentgen cosmic backgroun

    Quantum conductivity corrections in two dimensional long-range disordered systems with strong spin-orbit splitting of electron spectrum

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    We study quantum corrections to conductivity in a 2D system with a smooth random potential and strong spin-orbit splitting of the spectrum. We show that the interference correction is positive and down to the very low temperature can exceed the negative correction related to electron-electron interactions. We discuss this result in the context of the problem of the metal-insulator transition in Si-MOSFET structures.Comment: 8 pages, no figure

    On relativistic approaches to the pion self-energy in nuclear matter

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    We argue that, in contrast to the non-relativistic approach, a relativistic evaluation of the nucleon--hole and delta-isobar--nucleon hole contributions to the pion self-energy incorporates the s-wave scattering, which requires a more accurate evaluation. Therefore relativistic approach containing only these diagrams does not describe appropriately the pion self-energy in isospin symmetric nuclear matter. We conclude that, a correct relativistic approach to the pion self-energy should involve a more sophisticated calculation in order to satisfy the known experimental results on the near-threshold behaviour of the pion-nucleon (forward) scattering amplitude.Comment: 7 pages,1 figur

    Scaling in activated escape of underdamped systems

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    Noise-induced escape from a metastable state of a dynamical system is studied close to a saddle-node bifurcation point, but in the region where the system remains underdamped. The activation energy of escape scales as a power of the distance to the bifurcation point. We find two types of scaling and the corresponding critical exponents.Comment: 9 page

    P- and T-violating Schiff moment of the Mercury nucleus

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    The Schiff moment of the 199^{199}Hg nucleus was calculated using finite range P- and T-violating weak nucleon-nucleon interaction. Effects of the core polarization were considered in the framework of RPA with effective residual forces.Comment: 10 pages and 2 figures,to appear in Yad. Fi

    Schiff moment of the Mercury nucleus and the proton dipole moment

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    We calculated the contribution of internal nucleon electric dipole moments to the Schiff moment of 199^{199}Hg. The contribution of the proton electric dipole moment was obtained via core polarization effects that were treated in the framework of random phase approximation with effective residual forces. We derived a new upper bound dp<5.4×1024e|d_p|< 5.4\times 10^{-24} e\cdotcm of the proton electric dipole moment.Comment: 4 pages, 2 figures, RevTex

    Theory of microwave-induced oscillations in the magnetoconductivity of a 2D electron gas

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    We develop a theory of magnetooscillations in the photoconductivity of a two-dimensional electron gas observed in recent experiments. The effect is governed by a change of the electron distribution function induced by the microwave radiation. We analyze a nonlinearity with respect to both the dc field and the microwave power, as well as the temperature dependence determined by the inelastic relaxation rate.Comment: Extended version of cond-mat/0310668. 12 pages, 4 figures. V2: published version (minor changes, Fig. 4 corrected, references added

    Nuclear Magnetic Quadrupole Moments in Single Particle Approximation

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    A static magnetic quadrupole moment of a nucleus, induced by T- and P-odd nucleon-nucleon interaction, is investigated in the single-particle approximation. Models are considered allowing for analytical solution. The problem is also treated numerically in a Woods-Saxon potential with spin-orbit interaction. The stability of results is discussed.Comment: LATEX, 9 pages, 1 postscript figure available upon request from "[email protected]". BINP 94-4

    Universal limiting shape of worn profile under multiple-mode fretting conditions: theory and experimental evidence

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    We consider multiple-mode fretting wear in a frictional contact of elastic bodies subjected to a small-amplitude oscillation, which may include in-plane and out-of-plane translation, torsion and tilting (“periodic rolling”). While the detailed kinetics of wear depends on the particular loading history and wear mechanism, the final worn shape, under some additional conditions, occurs to be universal for all types and loading and wear mechanisms. This universal form is determined solely by the radius of the permanent stick region and the maximum indentation depth during the loading cycle. We provide experimental evidence for the correctness of the theoretically predicted limiting shape. The existence of the universal limiting shape can be used for designing joints which are resistant to fretting wear
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