Showing papers in "Journal of Experimental and Theoretical Physics in 1976"

Tearing instability in plasma configurations.

Abstract: The development of tearing instability in plasma containing a neutral diffusive layer and a magnetic field with a small but finite component perpendicular to the sheet is discussed. The effect of this component on electron orbits in the neighborhood of the neutral sheet is to stabilize the electron tearing mode even for very small amplitudes of the normal field. The development of the ion tearing mode of given wavelength is found to be possible only in the ''gap'' corresponding to a certain restricted range of values of the normal magnetic-field component for which its effect on ion orbits in the neutral sheet can still be neglected whilst the stabilizing contribution of magnetized electrons to the plasma permittivity is already small. It is shown that gaps of this kind can appear only when the current in the sheet is large enough. When the value of the normal magnetic-field component lies below the instability region, the plasma states are metastable with respect to the excitation of the ion tearing mode.

New mechanism for superconductivity: pairing between spatially separated electrons and holes

Abstract: A new mechanism for superconductivity, based on the pairing of spatially separated electrons and holes that arises from their Coulomb attraction, is proposed A gap in the single-particle excitation spectrum is found The roles of interband transitions, the electron-phonon interaction, scattering by impurities, spin-orbit interaction, etc are analyzed The critical current is calculated Possible experiments are discussed

Turbulent mixing at contact surface accelerated by shock waves

Abstract: 1M. N. Mikheeva, M. B. Tsetlin, A. A. Teplov, V. M. Golyanov, and A. P. Demidov, Pis'ma Zh. Eksp. Teor. Fiz. 15, 303 (1972) [JETP Lett. 15, 213 (1972)]. 2V. M. Golyanov, M. N. Mikheeva, and M. B. Tsetlin, Zh. Eksp. Teor. Fiz. 68, 736 (1975) [SOY. Phys. JETP 41, 365 (1975)]. 3V. M. Golyanov and M. N. Mikheeva, Zh. Eksp. Teor. Fiz. 70, 2236 (1976) [SOY. Phys. JETP 43, (1976)]. 4H. Sixl, Phys. Lett. 53A, 333 (1975). 5V. M. Golyanov, M. N. Mikheeva, A. P. Demidov, and A. A. Teplov, Zh. Eksp. Teor. Fiz. 58, 528 (1970) [SOY. Phys. JETP 31, 283 (1970)]. 6G. Bergmann, Phys. Rev. B7, 4850 (1973). 7A. A. Teplov, M. N. Mikheeva, and V. M. Golyanov, Zh. Eksp. Teor. Fiz. 68, 1108 (1975) rSov. Phys. JETP 41, 549 (1975)]. SA. A. Teplov, M. N. Mikheeva, V. M. Golyanov, and A. N. Gusev, Zh. Eksp. Teor. Fiz. 71, No.9 (1976) [SOY. Phys. JETP 44, No.9 (1976)]. sL. P. Gor'kov, Zh. Eksp. Teor. Fiz. 37, 1407 (1959) [SOY. Phys. JETP 10, 998 (1960)].

Nonleptonic Decays of K Mesons and Hyperons

Abstract: Nonleptonic decays of ordinary hadrons are considered within the framework of the renormalizable vector schemes for weak interactions An asymptotically free theory is put forward for strong interactions All the independent operators in the effective Hamiltonian are enumerated, and expansion coefficients which take into account strong interactions at short distances are determined The valence quark model is used to estimate the matrix elements of the operators Transitions with deltaT=3/2 are evaluated in terms of a single parameter The large magnitude of the amplitudes for deltaT=1/2 transitions is explained in terms of an operator producing the product of two scalars (or pseudoscalars), which is due to the presence of strong interaction in any model This explanation rests on the assumption of small bare quark masses, which characterize violations of chiral symmetry A number of relationships, which agree with experiment, are obtained Estimates show that the introduction of right-handed currents is not essential for nonleptonic decays

Existence of a hexagonal relief on the surface of a dielectric fluid in an external electrical field

Abstract: Institute of Automation and Electrometry, Siberian Division, USSR Academy of Sciences (Submitted November 20, 1975; resubmitted February 12, 1976) Zh. Eksp. Teor. Fiz. 71, 262-272 (July 1976) The transformation of a horizontal surface of a dielectric fluid into an immobile corrugated surface following application of an external electric field is studied. The destruction of the plane boundary as a result of development of instability in fields exceeding a critical value brings the system to a stable stationary state.

Superconductivity in crystals without symmetry centers

Abstract: We consider the effect of spin-orbit interaction on the paramagnetic properties of superconducting crystals having a lattice without symmetry center. Systems of this type include superconducting metals with polar-symmetry lattice V/sub 2/Hf and VRu. Arguments are advanced favoring the assumption that there may be no symmetry center in a lattice of layered dichalcogenide metals with incommensurate charge-density wave or of intercalated layered metals. The paramagnetic susceptibility and the paramagnetic limit H/sub ps/ of the upper critical magnetic field are obtained for such superconductors as functions of the relative spin-orbit interaction ..cap alpha..=epsilon/sub 1//..delta.. (0), of the degree of purity of the crystals lambda=1/2tau..delta.. (0), of the temperature, and of the field direction. The quantities chi and H/sub ps/ are anisotropic, and H/sub ps/ can greatly exceed the Chandrasekhar-Clogston paramagnetic limit H/sub p/. The experimental data for H/sub c/ in 2H-NbSe/sub 2/ and TaS/sub 2/(Py)/sub 1/2/ are discussed from the point of view of the results.

Plasma turbulence near the lower-hybrid resonance

Abstract: We study non-linear processes in the frequency range close to the lower hybrid frequency ..omega../sub L/. For sufficiently short-wavelength oscillations (kv/sub T i/very-much-greater-than..omega../sub H i/) the main one of those is, for a wide temperature range, T/sub e/approximately-greater-thanT/sub i/, induced scattering by electrons. We study the non-linear stage of the parametric instability in the frequency range ..omega..approximately-greater-than..omega../sub L/. We show that if one is just above criticality plasma wave turbulence becomes strong. We obtain the equations describing the strongly non-linear regime. We study their properties.

Electric conductivity of a non-ideal plasma

Abstract: S Y Manakov, Zh Eksp Teor Fiz 65, 505 (1973) [SOY Phys JETP 38, 248 (1974)1-8L A Takhtadzhyan, Zh Eksp Teor Fiz 66, 476 (1974) [SOy Phys JETP 39, 228 (1974)] sM J Ablowitz, and A C Newell, J Math Phys 14, 1277 (1973) IOTransl in: Nelinielnaya teoriya rasprostraneniya voln (Non­linear Theory of Wave Propagation) Mir, 1970 IIA Y Gurevich and L P Pitaevskii, Zh Eksp Teor Fiz 65, 590 (1973) [SOY Phys JETP 38, 291 (1974)] 12E Ya Khruslov, Pis'ma Zh Eksp Teor Fiz 21, 469 (1975) [JETP Lett 21, 217 (1975)] 13 A Erdelyi

A bound on the proton electric dipole moment derived from atomic experiments

Abstract: The upper bound d/e<55 x 10/sup -19/ cm on the proton electric dipole moment (EDM) d is derived from the experimental upper bound for the EDM of the cesium atom in a state with F=4 Similar measurements on an F=3 state might improve this result by a factor of 15 An upper bound on the magnetic quadrupole moment of the nucleus (which might be induced, for example, by the EDM of the valence nucleon) is also derived from the same experiment The search for the proton EDM in experiments with polar molecules is discussed

First-order magnetic phase transitions and fluctuations

Abstract: In some magnetic transitions the fluctuations are so strong that transitions of the second order, which are in principle possible according to the Landau theory, are transformed into transitions of the first order. Antiferromagnetic transitions in UO/sub 2/, MnO, TbAs, NdTe etc. cubic lattices are considered. Calculations performed by means of the epsilon expansion show that in all cases mentioned above transitions of the second order are not possible, in accordance with the experimental situation for MnO and UO/sub 2/. Some possible types of transitions of the first order are considered.