Rare top quark decays in extended models

Abstract

Flavor changing neutral currents (FCNC) decays t to H + c, t to Z + c, and H to t + bar{c} are discussed in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions where FCNC decays may take place at tree-level and are only suppressed by the mixing between ordinary top and charm quarks, which is poorly constraint by current experimental values. The non-manifest case is also briefly discussed.

Comments: Contributed talk given at the 10th Mexican Workhop on Particles and Fields, Morelia, Michoacan, Mexico, 7-12 Nov 2005