Regge Behaviour from an Environmentally Friendly Renormalization Group

The asymptotic behaviour of cubic field theories is investigated in the Regge limit using the techniques of environmentally friendly renormalization, environmentally friendly in the present context meaning asymmetric in its momentum dependence. In particular we consider the crossover between large and small energies at fixed momentum transfer for a model scalar theory of the type phi^2 psi. The asymptotic forms of the crossover scaling functions are exhibited for all two particle scattering processes in this channel to one loop in a renormalization group improved perturbation theory.Comment: 9 pages text, one figure, LaTeX, uses psfig.sty. Revised version submitted to Phys. Lett. B., besides minor changes a figure to illustrate the conventions and a discussion of the full crossover function have been adde

A tunable, dual mode field-effect or single electron transistor

A dual mode device behaving either as a field-effect transistor or a single electron transistor (SET) has been fabricated using silicon-on-insulator metal oxide semiconductor technology. Depending on the back gate polarisation, an electron island is accumulated under the front gate of the device (SET regime), or a field-effect transistor is obtained by pinching off a bottom channel with a negative front gate voltage. The gradual transition between these two cases is observed. This dual function uses both vertical and horizontal tunable potential gradients in non-overlapped silicon-on-insulator channel

Reptiles, Squamata, Parque Natural Municipal da Taquara, municipality of Duque de Caxias, state of Rio de Janeiro, Southeastern Brazil

Herein we report a list of the reptiles from Parque Natural Municipal da Taquara, municipality of Duque deCaxias, state of Rio de Janeiro, southeastern Brazil, an area situated in the Atlantic Rainforest Domain. The study wascarried out from September 2006 to October 2008. We recorded 31 species of Squamate reptiles: one species of thefamily Amphisbaenidae; eight species of lizards of the families Anguidae (n = 1), Gekkonidae (1), Phyllodactylidae (1),Polychrotidae (1), Scincidae (1), Teiidae (2), and Tropiduridae (1); and 22 species of snakes of the families Boidae (2),Colubridae (6), Dipsadidae (11), Elapidae (1), and Viperidae (2). Our study indicates that the PNMT is an important area forthe conservation of the Squamate reptile assemblages that inhabit lowlands of Atlantic Rainforest in Brazil

Ultracold neutrons, quantum effects of gravity and the Weak Equivalence Principle

We consider an extension of the recent experiment with ultracold neutrons and the quantization of its vertical motion in order to test the Weak Equivalence Principle. We show that an improvement on the energy resolution of the experiment may allow to establish a modest limit to the Weak Equivalence Principle and on the gravitational screening constant. We also discuss the influence of a possible new interaction of Nature.Comment: Revtex4, 4 pages. Discussion on the equivalence principle altered. Bound is improve