Signals from Flavor Changing Interactions in Extended Models

In the contest of a Two Higgs Doublet Model without flavor conservation, the presence of Flavor Changing Neutral Scalar Currents may affect in particular the couplings of the top quark. Some ideas on how to look for new signals from Flavor Changing Interactions at the next generation of lepton colliders are presented.Comment: 2 pages, latex file, gzip-compressed and uuencoded; invited talk at the European Physical Society Conference on High Energy Physics, Brussels, July 1995; to be published in the proceeding

Flavor Changing Neutral Currents and the third family

We investigate the possibility of having sizable effects from flavor changing neutral currents at the tree level in a particular class of Two Higgs Doublet Models. Constraints from existing experimental information are discussed. Some interesting signals at the future generation of lepton colliders are illustrated.Comment: 6 pages, 1 Postscript figures, uses epsf.sty, to appear in the Proceedings of the XXXIst Rencontres de Moriond Les Arcs, France, March 199

Associated Top-Higgs production at future colliders

We discuss the relevance of the associated production of a Higgs boson with a pair of top-antitop quarks at both the LHC and a future high energy e^+e^- collider.Comment: 4 pages, 4 figures. Talk given at DPF 2000: The Meeting of the Division of Particles and Fields of the American Physical Society, Columbus, Ohio, 9-12 Aug 200

Signals from Flavor Changing Scalar Currents at the Future Colliders

We present a general phenomenological analysis of a class of Two Higgs Doublet Models with Flavor Changing Neutral Currents arising at the tree level. The existing constraints mainly affect the couplings of the first two generations of quarks, leaving the possibility for non negligible Flavor Changing couplings of the top quark open. The next generation of lepton and hadron colliders will offer the right environment to study the physics of the top quark and to unravel the presence of new physics beyond the Standar Model. In this context we discuss some interesting signals from Flavor Changing Scalar Neutral Currents.Comment: 5 pages, 2 EPS figures, requires Latex2e, snow2e.cls (included) and graphics.st

Flavor Changing Neutral Currents at mu^+mu^- Colliders

We illustrate the possibility of observing signals from Flavor Changing Neutral Currents, originating from the scalar sector of a Two Higgs Doublet Model. In particular, we focus on the tree level process mu^+ mu^- --> tbar c + cbar t, via scalar exchange in the s-channel, as a distinctive process for mu^+ mu^- colliders.Comment: 10 pages, 1 EPS figure, requires LaTeX, epsf.st

Higgs boson production in association with top quarks in the POWHEG BOX

We present results from the analytic calculation of top+antitop+Higgs hadronic production at Next-to-Leading Order in QCD interfaced with parton-shower Monte Carlo event generators in the POWHEG BOX framework. We consider kinematic distributions of the top quark and Higgs boson at the 8 TeV Large Hadron Collider and study the theoretical uncertainties due to specific choices of renormalization/factorization scales and parton-showering algorithms, namely PYTHIA and HERWIG. The importance of spin-correlations in the production and decay stages of a top/antitop quark is discussed on the example of kinematic distributions of leptons originating from the top/antitop decays. The corresponding code is now part of the public release of the POWHEG BOX.Comment: 15 pp, 14 figure