2000/11/30 by Santi Bejar, Santi Béjar, Jaume Guasch +2 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/s0550-3213(01)00044-x
published as Nucl.Phys.B600:21-38,2001 · 18 pages, LaTeX, 5 figures, 1 table. References added
arxiv created 2001/02/13 · openalex publication_date 2001/04/01 · arxiv updated 2010/03/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Decays of the top quark induced by flavor changing neutral currents (FCNC) are known to be extremely rare events within the Standard Model. This is so not only for the decay modes into gauge bosons, but most notably in the case of the Higgs channels, e.g. t-> HSM+c, with a branching fraction of 10-13 at most. Therefore, detection of FCNC top quark decays in a future high-energy, and high-luminosity, machine like the LHC or the LC would be an indisputable signal of new physics. In this paper we show that within the simplest extension of the SM, namely the general two-Higgs-doublet model, the FCNC top quark decays into Higgs bosons, t->(h0,H0,A0)+c, can be the most favored FCNC modes -- comparable or even more efficient than the gluon channel t-> g+c. In both cases the optimal results are obtained for Type II models. However, only the Higgs channels can have rates reaching the detectable level (10-5), with a maximum of order 10-4 which is compatible with the charged Higgs bounds from radiative B-meson decays. We compare with the previous results obtained in the Higgs sector of the MSSM.