Centrality dependence of charged hadron transverse momentum spectra in Au+Au collisions from sqrt[s(NN)]=62.4 to 200 GeV

We have measured transverse momentum distributions of charged hadrons produced in Au+Au collisions at sqrt[s(NN)]=62.4 GeV. The spectra are presented for transverse momenta 0.25相似文献   

The thermometry system of superconducting magnets test bench for the Nica accelerator complex

Precise temperature control in various parts of the magnet and thermostat is one of the vital problems during cryogenic tests. The report describes design of the thermometry system, developed at LHEP JINR. This system is the operational prototype for the NICA thermometry system. Besides, the report describes generic software tools, developed for the TANGO-based control system web client software design.     

Specific features of the structural transformations in La1 − x Ca x Mn0.98 57Fe0.02O3 + δ (x = 0.05−0.50)

The specific features of the structural transformations in La_{1 ? x} Ca _x Mn_0.98 ⁵⁷Fe_0.02O_{3 + δ} (x = 0.05?0.50) at different Ca concentrations have been studied using Mössbauer spectroscopy and X-ray diffraction. Variations of the heat treatment conditions (annealing in vacuum and in air) cause reversible phase transitions. For calcium concentrations to 20%, a whole set of phases with reversible structural transitions, such as PnmaII ? PnmaI ? $R\bar 3c$ , can be obtained using the corresponding heat treatment. The phases are successively suppressed with increasing calcium concentration. The rhombohedral phase is suppressed for x = 0.20. When the Ca concentration exceeds 20%, the PnmaII phase is suppressed; as a result, the PnmaI phase with equal concentrations of Mn⁴⁺ and calcium stable during any heat treatments remains. The specific features of phase formation in the La_{1 ? x} Ca _x Mn_0.98 ⁵⁷Fe_0.02O_{3 + δ} compound doped with calcium and in the basis LaMnO_{3 + δ} compound have been compared.     

Reversible low-temperature transition in LaMnO<Subscript>3+δ</Subscript>

The evolution with a decrease in temperature of the basic rhombohedral structure of the LaMnO_3+δ compound having a specified constant oxygen concentration is considered. The X-ray diffraction analysis shows that a transition from rhombohedral to monoclinic phase begins at a temperature close to 200 K. The important feature of the revealed low-temperature phase transition is its reversibility with heating to room temperature. A deformation mechanism of structural phase transitions based on uniform distortions of a perovskite block with a doubled lattice parameter is proposed. The results of the analysis of the symmetry of atomic positions are in favor of two-step routes of phase transitions through dilatation and twinning.     

Corank 1 Singularities of Stable Smooth Maps and Special Tangent Hyperplanes to a Space Curve

Let γ be a smooth generic curve in ?P ₃. Denote by C the number of its flattening points, and by T the number of planes tangent to γ at three distinct points. Consider the osculating planes to γ at the flattening points. Let N denote the total number of points where γ intersects these osculating plane transversally. Then T ≡ [N + θ(γ)C]/2 (mod 2), where θ(γ) is the number of noncontractible components of γ. This congruence generalizes the well-known Freedman theorem, which states that if a smooth connected closed generic curve in ?³ has no flattening points, then the number of its triple tangent planes is even. We also give multidimensional analogs of this formula and show that these results follow from certain general facts about the topology of codimension 1 singularities of stable maps between manifolds having the same dimension.