New Physics effects in the flavor-changing neutral couplings of the Top quark

We survey the flavor-changing neutral couplings (FCNC) of the top quark predicted by some extensions of the Standard Model: THDM, SUSY, L-R symmetric, TC2, 331, and models with extra quarks. Since the expected sensitivity of the LHC and ILC for the tcV (V=\gamma,g,Z) and tcH couplings is of order of a few percent, we emphasize the importance of any new physics effect that gives a prediction for these FCNC couplings within this limit. We also review the constraints imposed on these couplings from low-energy precision measurements.Comment: 19 pages, 7 figures. Accepted as a review paper in Int. J. of Mod. Phys.

The triple-pomeron regime and the structure function of the pomeron in the diffractive deep inelastic scattering at very small x

Misprints and numerical coefficients corrected, a bit of phenomenology and one figure added. The case for the linear evolution of the unitarized structure functions made stronger.Comment: KFA-IKP(Th)-1993-17, Landau-16/93, 46 pages, 14 figures upon request from N.Nikolaev, [email protected]

Os meios de comunicação e a prática política The midia and political practice

Recorrendo à idéia de campo de Bourdieu busca-se demonstrar que, por forte que seja a presença dos meios de comunicação na dinâmica política contemporânea, a política não se subordina a ela, pois constitui campo específico, com regras e lógica próprias.<br>Using Bourdieu's idea of field it is shown that, however strong the presence of the communication media in contemporary political dynamics, politics is not subordinated to it but forms a specific field with its own rules and logic