Probing mu-term Generation Mechanism in String Models

We give a generic method to select a realistic $\mu$-term generation mechanism based on the radiative electroweak symmetry breaking scenario and study which type is hopeful within the framework of string theory. We discuss effects of the moduli F-term condensation and D-term contribution to soft scalar masses.Comment: Latex, 17 pages, 4 Postscript figure

Drinfel'd Twisted Superconformal Algebra and Structure of Unbroken Symmetries

We investigate deformed superconformal symmetries on non(anti)commutative (super)spaces from the point of view of the Drinfel'd twisted symmetries. We classify all possible twist elements derived from an abelian subsector of the superconformal algebra. The symmetry breaking caused by the non(anti)commutativity of the (super)spaces is naturally interpreted as the modification of their coproduct emerging from the corresponding twist element. The remaining unbroken symmetries are determined by the commutative properties of those symmetry generators possessing the twist element. We also comment on non-canonically deformed non(anti)commutative superspaces, particularly those derived from the superconformal twist element (\mathcal{F}_{\mathrm{SS}}).Comment: 13 pages, LaTeX; typos of published version and references are correcte

Magnetic-Field-Induced Superconductivity in Eu_<0.8>Sn_<0.2>Mo_6S_<7-y>Se_y (Transport and Fermiology)

The electrical resistance of Eu_Sn_Mo_6S_Se_y (0≤y≤0.7) was measured under the magnetic fields up to 230 kOe. The hysteresis of the resistance was observed in the field range where the superconductive-normal-superconductive transitions appear. Analysis of the hysteresis provides a direct evidence that the magnetic-field-induced superconductivity of these compounds is caused by the Jaccarino-Peter compensation mechanism