No abstract available

[en] Only table to be replaced in the article of the 1st October letter is published

[en] A Nambu-Jona-Lasinio model with vector interactions is considered. Vector mesons are found to reduce significantly the partial restoration of chiral symmetry at normal nuclear density. The quark loop term is expanded in terms of the field amplitudes thus yielding on-shell meson masses. Results are compared with those obtained in gradient expansions. The model can describe on-shell π, ρ and ω mesons as bound qantiq excitations but it is unable to form bound a₁ and f₁ mesons

[en] The ground state of the appropriate generalization of the impurity Anderson model for valence fluctuations between two realistic Tm⁺² and Tm⁺³ configurations is obtained, in the narrowband limit, using the Lanczos' method. This limit describes the strong-coupling fixed point of renormalization group treatments for intermediate valence and Kondo impurities. The resulting ground state is highly degenerate and contains states of total angular momentum 0, 3/2, 2, 5/2, 4 and 9/2. The crystal electric field or an applied magnetic field should split the degeneracy favouring the magnetic states. As found in TmSe, the Tm magnetic moment is anomalously small

[en] Evidence for irregular scattering in a system of two vortex pairs is presented. Depending on impact parameter, arbitrarily complicated motion can be realized. The method of Poincare surfaces of section for scattering maps is used to determine the boundary of the irregular region. The methods presented here can also be applied to other classical scattering problems

[en] We have measured the frequency shift of the counterflow-induced peak in the NMR spectrum of the flare-out texture in rotating ³He in a vortex-free state. From a comparison with the calculated shifts, the temperature dependence of the dipolar velocity at P=5.0 and 29.3 bar has been deduced. Our results are in good agreement with theoretical predictions

[en] We have observed a rapid decrease in the lifetime of a homogeneously precessing domain in ³He-B at a temperature of 0.4T_c. This phenomenon does not depend on pressure, magnetic field, or on the presence of ⁴He covering the surface of the chamber. We suppose this effect is the result of a magnetic relaxation through some unknown channel. Catastrophic relaxation may possibly be connected to some new phase transition in ³He

[en] Superstrings, when moving across the 10-dimensional (with the six surplus dimensions compactified) space, will, due to quantum effects, induce a large cosmological constant on a 4-dimensional submanifold. If the latter is topologically nontrivial, then the supergravity theory surviving in it at dimensional reduction gives rise to the topological Casimir effect. A combined action of the latter one and the cosmological constant mentioned leads to an inflation of the given 4-dimensional submanifold which may be interpreted as a quantum birth of the 4-dimensional topologically nontrivial universe from a superstring

[en] The Wigner distribution function of a fermion is constructed by using its coherent state labelled by anti-commuting c-numbers. The quantum transport equation and its path-integral solution are also presented

[en] Thin crystals of RBa₂Cu₃0_7-x (R = Eu, Gd) were irradiated with 50 keV He⁺ ions at 15 K and 300 K, and their structure was studied in situ via transmission electron microscopy. An orthorhombic-to-tetragonal phase transition was observed (at both irradiation temperatures) at fluences around 4.10¹⁵ He⁺/cm². Amorphization occurs in the LT-irradiated samples at fluence ≥ 10¹⁶ He⁺/cm². Radiation-induced damage (dislocation loops) was also identified, for the first time, in the orthorhombic phase