The anomalous 3-boson couplings as an implication of the Higgs sector

We discuss the possible new electroweak interactions which may be generated by the Higgs sector at the scale of theZ mass. For this purpose, we give a set ofSU(2)×U(1) gauge invariant operators constructed in terms ofW, Z, γ and Higgs fields which in the unitary gauge describe all possible γWW andZWW anomalous couplings. The dimension of these operators varies from 6 to 12. This fact allows us to consider various scenaria for the manifestations of the New Physics. We conclude that the underlying dynamics induced by the Higgs sector can be tested through a model-independent amplitude analysis of gauge boson pair production at LEP2 and future colliders.     

Conductance of a multiterminal ballistic wire

JETP Letters - An experimental study of the two-, three-, and four-terminal resistance of a ballistic wire is carried out. The wire is fabricated on the basis of high-mobility 2D electron gas in an...     

Structural characterisation of Sb-based heterostructures by X-ray scattering methods

Antimonide-based superlattices dedicated to the elaboration of opto-electronic devices have been studied by X-ray scattering techniques. In particular, specular and non-specular X-ray reflectometry experiments have been performed on two MBE-samples elaborated with different shutter sequences at the interfaces. The results have shown a limitation of the incorporation of Sb species in the subsequent InAs layer for one of the samples, as expected.Then, a study on a InGaAs-cap layer/(InGaAs/AlAsSb)_N superlattice grown on a InGaAs/InP buffer layer by both specular X-ray reflectometry and High resolution X-ray diffraction is reported. In particular, the results have revealed the presence of a highly disturbed thin-layer on top of the MOVPE-made GaInAs, whose presence has been explained by In-concentration modification during the desoxidation procedure at the surface of the MOVPE-made GaInAs.Beside the results on the Sb-based heterostructures, the use of X-ray scattering metrology as a routinely working non-destructive testing method has been emphasized.     

Association of poly-N-[tris(hydroxymethyl)methyl] acrylamide with a water soluble β-cyclodextrin polymer

An acrylic polymer with pendent adamantyl groups was synthesized and its properties in an aqueous solution with a β-cyclodextrin (βCD) epichlorhydrin polymer examined. Viscosity properties of precursor and modified polymers show differences at low concentrations, but not at higher concentration probably due to very important hydrogen bonds which prevent the formation of intermolecular hydrophobic bonds. The association of both complementary polymers through the inclusion of adamantyl groups is evidenced by phases separation occurrence. Phase diagrams were established at two different concentrations of polymers. We have shown a maximal association of both polymers at these two concentrations, for the same ratio βCD moles/adamantyl groups: 2.4. Salt addition favors this association and displaces the two phases zone to smaller concentrations of modified polymer. Further, 4-nitrophenol can be extracted by the concentrated phase resulting from mixture of solutions of guest and host polymers, pointing out the availability of the associated phase to trap organic molecules.