Some Multi-Quark Potentials, Pseudo-Potentials and AdS/QCD

The static three-quark potential and pseudo-potential of a pure SU(3) gauge theory are studied in a five-dimensional framework known as AdS/QCD. The results support the Y-ansatz for the baryonic area law. A comparison with the quark-antiquark calculations shows the universality of the string tension as well as the spatial string tension. We also discuss extensions to SU(N) gauge theories.Comment: 18 pages, 7 figures; v2: a few sentences added and typos correcte

Stimulated Raman backscattering of laser radiation in deep plasma channels

Stimulated Raman backscattering (RBS) of intense laser radiation confined by a single-mode plasma channel with a radial variation of plasma frequency greater than a homogeneous-plasma RBS bandwidth is characterized by a strong transverse localization of resonantly-driven electron plasma waves (EPW). The EPW localization reduces the peak growth rate of RBS and increases the amplification bandwidth. The continuum of non-bound modes of backscattered radiation shrinks the transverse field profile in a channel and increases the RBS growth rate. Solution of the initial-value problem shows that an electromagnetic pulse amplified by the RBS in the single-mode deep plasma channel has a group velocity higher than in the case of homogeneous-plasma Raman amplification. Implications to the design of an RBS pulse compressor in a plasma channel are discussed.Comment: 11 pages, 3 figures; submitted to Physics of Plasma

Cold Quark Matter, Quadratic Corrections and Gauge/String Duality

We make an estimate of the quadratic correction in the pressure of cold quark matter using gauge/string duality.Comment: 7 pages; v.2: reference added; v.3: reference and comments added, version to appear in PRD; v4. final version to appear in PRD; v.5: key reference adde

Normal state diamagnetism of charged bosons in cuprate superconductors

Normal state orbital diamagnetism of charged bosons quantitatively accounts for recent high-resolution magnetometery results near and above the resistive critical temperature Tc of superconducting cuprates. Our parameter-free descriptions of normal state diamagnetism, Tc, upper critical fields and specific heat anomalies unambiguously support the 3D Bose-Einstein condensation at Tc of preformed real-space pairs with zero off-diagonal order parameter above Tc, at variance with phase fluctuation (or vortex) scenarios of the "normal" state of cuprates.Comment: 10 pages, 4 figure

Separated spin-up and spin-down evolution of degenerated electrons in two dimensional systems: Dispersion of longitudinal collective excitations in plane and nanotube geometry

Applying the separated spin evolution quantum hydrodynamics to two-dimensional electron gas in plane samples and nanotubes located in external magnetic fields we find new kind of wave in electron gas, which is called the spin-electron acoustic wave. Separate spin-up electrons and spin-down electrons evolution reveals in replacement of the Langmuir wave by the couple of hybrid waves. One of two hybrid waves is the modified Langmuir wave. Another hybrid wave is the spin-electron acoustic wave. We study dispersion of these waves in two dimensional structures of electrons. We also consider dependence of dispersion properties on spin polarisation of electrons in external magnetic field.Comment: 5 pages, 5 figure