Signals for compositeness atep colliders: “Leptogluons” and exotic colored vectorbosons

Production rates and signals for coloroctet leptonsl ₈ atep machines like Hera and a \(\sqrt s = 2\) TeV collider are presented. In case of very heavy leptogluons:m ₈≈0(100 GeV) we argue that rates based on direct electron-gluon fusion are possibly strongly overestimated in the literature. In composite models the appearance of leptogluons always implies the existence of color exotic vectorbosons. Therefore we considerl ₈ production in electron-quark scatterings. We find that even at HERA energies such reactions should be detectable if there is nearby compositeness (Λ _H ～ several TeV) and the mass of the coloroctet neutrinom _v8<180 GeV. From such events it would be possible to extract information on the deeper structure of the preon model.     

Phenomenology of composite colored weak bosons

In composite models of quarks, leptons and weak bosons whereW-constituents are colored objects, color octet partners ofW ^± andZ ⁰ are predicted. We study in detail the phenomenology of these particles. Independent of the specific model one expects a color octet isotriplet of vector bosons (W ₈ ^± ,Z ₈ ⁰ ) with mass in the range of 100–200 GeV, and a color octet isosinglet vector bosonV ₈ ⁰ with substantially larger mass, due to mixing with the gluon. Moreover, relatively light color octet excitations of the leptons appear, while the existence of “color exotic” partners of the quarks is model dependent. These particles decay mainly into a lepton (quark) and a gluon. We construct the couplings ofW ₈ ^± ,Z ₈ ⁰ andV ₈ ⁰ to ordinary and “color exotic” fermions. The signals of color octet weak bosons in low energy weak reactions are explored in detail. The production cross section ofW ₈ ^± (Z ₈ ⁰ ) in hadron-hadron collisions is calculated for \(0.54TeV \leqq \sqrt s \leqq 20TeV\) . Various decay modes of colored weak bosons are studied. The most prominent decay signatures ofW ₈ ^± andZ ₈ ⁰ are events of the type (l ^+-: charged lepton;j: hadronic jet; : missing transverse momentum). The present CERN \(p\bar p\) collider data on such events are discussed in the light ofW ₈ ^± andZ ₈ ⁰ decays. If colored weak bosons are not found with a mass less than ～250 GeV composite model building will be strongly restricted.     

Geometrical connection between the equations of the special quasiclassical model of atomic systems

We study the geometrical connection between the fundamental equations of the quasiclassical model proposed by Rodimov to explain the behavior of microparticles in atomic systems in his monograph Self-Oscillating Quantum Mechanics; the v and u equations. It is shown that the geometry of the spaces for the v and u equations is different, but the metrical coefficients are related by simple algebraic relations.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 5, pp. 66–70, May, 1986.The author thanks Go I. Flesher for interest in the work and useful critical discussions and also I. L. Bukhbinder for fruitful discussions of the fundamental aspects of the work.     

Trap centers in Au-implanted MOS structures

Trap centers in the Si-SiO₂ interface region of MOS structures doped by ion implantation of gold have been investigated using constant capacitance deep level transient spectroscopy (CC-DLTS). Gold doses of 10¹²–3 × 10¹³ cm^–2 were implanted into the back surface of the wafers and were then redistributed during a diffusion anneal for 30 min at 1100° or 900° C. Three Au-related trap levels have been observed in the interface region, which were attributed to the Au-donor (E _v +0.35 eV), the Au-acceptor (E _v +0.53 eV), and the Au-Fe complex (E _v +0.45 eV). The trap concentration profiles show that the Si-SiO₂ interface affects the Au concentration in a depth range of 1 m from the interface and that gettering of Au occurs at the interface. The interface state density is independent of the Au concentration at the interface even for concentrations of 10¹⁵ cm^–3.     

Field dependent critical fluctuations aboveT g in the ESR line width of the spin glassAgMn

The ESR of the spin glassAgMn (2.7 and 9.6 at %) has been investigated below and aboveT _g(0.1T _g<T<5T _g) at various microwave frequencies. The analysis yields:1) No explicit frequency dependence but strong magnetic field effects, inherent with ESR-experiments.2) Part of the excess line width is identified as critical spin fluctuations, following a power law. However, because of the presence of the applied field, the reduced temperaturet is not a good scaling variable. We choose the non-linear susceptibility X _s divided byH ², which scales as the order parameter susceptibility. The experiment yieldsW _ex(X _s /H ²) ^p ,p=0.42. From this we deduce z3.     

Structural changes of Zr x Cu100-x metallic glasses investigated by low temperature specific heat measurements

Amorphous alloys of Zr _x Cu_100–x (55x72) quenched from the melt are investigated by low temperature specific heat measurements. The influence of concentrationx, temperature of the melt before the quenching process and heat treatment on the electronic density of states, the Debye temperature and the superconducting transition temperature is examined. The latter one is the most affected value by structural relaxation while the specific heat in the normal conducting region remains nearly unchanged.     

Enhanced ionic conductivity at the interface between sapphire and solid lithium iodide

We have studied the enhanced ionic conductivity of thin films of LiI evaporated onto a planar sapphire surface carrying interdigital Au-electrodes. The interface conductivity parallel to the surface was measured in situ for increasing film thickness, up to 3,000 Å. The specific conductivity of LiI in the first 300 Å — adjacent to the sapphire — was found to exceed the bulk conductivity of LiI by nearly one order of magnitude. From our observations we conclude that the specific conductivity of LiI decreases exponentially with distance from the sapphire surface reaching the bulk LiI-value only at a distance of 3,000 Å. The conductivity of a 350 Å thick film varies with temperature (25°CT120°C) in accordance with an activation energy of 0.40±0.04 eV. This is in good agreement with the activation energy of bulk LiI in the extrinsic region.     

Excited states in126Ba

The K=3/2 ₁ ^T rotational band has been identified in⁹⁹Y with a band-head energy of 536 keV. This result is in contradiction with previously reported data, but is in agreement with predictions of the IBFM/PTQM model.     

A new high-spin isomer in 39 97 Y58

An isomeric state at 3,523 keV excitation energy in⁹⁷Y with a half-life of 144(10) ms has been discovered with the fission-product separator JOSEF. This isomer is depopulated through aγ transition of 162 keV. AnE3 multipolarity for this transition is consistent with the measured conversion coefficients ofα _K =0.98(20) andα _T =1.00(19). Subsequent electromagnetic transitions populate several new⁹⁷Y levels which have high spins. For the isomer the three-quasiparticle configuration [πg _9/2?ν(h _11/2,g _7/2)]27/2^? is proposed. TheE3 transition with a strength about 2 single-particle units is supposed to be of the typeh ₁₁ ^2/+1 →d ₅ ^2/?1 . These findings provide evidence for the rapid shape transition atA?100 since they indicate shell-model character of ₃₉ ⁹⁷ Y₅₈ even at high excitation energies while the immediate neighbour ₃₉ ⁹⁸ Y₅₉ contains a rotational band based on a level at 495 keV.     

Influence of a continuous quenching procedure on the initial stages of spinodal decomposition

Instead of the standard assumption in the theory of phase separation where an instantaneous quench from an initial equilibrium state to the final state in the two-phase region is assumed, we consider the more realistic situation that the change of the external control parameter (e.g. temperature) can only be performed with finite rates. During the initial stages of spinodal decomposition the system then has some memory of the states intermediate between the initial and the final one. This influence of the finite quench rate in continuous quenching procedures is studied within the linearized theory of spinodal decomposition, with the Langer-Baron-Miller decoupling, and with Monte Carlo simulations. Both the case of thermally activated mobilities (applicable to solid metallic alloys) and the case of nearly temperature-independent mobilities (applicable to fluid polymer mixtures) are treated, and possible experimental applications are discussed. We find drastic deviations from the standard instantaneous quench situations in all cases of experimental interest.