Ferreira, Pedro MiguelSilva, João Paulo2013-01-252013-01-252011-03-22FERREIRA, P. M.; SILVA, João P. - Abelian symmetries in the two-Higgs-doublet model with fermions. Physical Review D. ISSN 1550-7998. Vol. 83, n.º 6 (2011).1550-7998http://hdl.handle.net/10400.21/2073We classify all possible implementations of an Abelian symmetry in the two-Higgs-doublet model with fermions. We identify those symmetries which are consistent with nonvanishing quark masses and a Cabibbo-Kobayashi-Maskawa quark-mixing matrix (CKM), which is not block-diagonal. Our analysis takes us from a plethora of possibilities down to 246 relevant cases, requiring only 34 distinct matrix forms. We show that applying Z(n) with n >= 4 to the scalar sector leads to a continuous U(1) symmetry in the whole Lagrangian. Finally, we address the possibilities of spontaneous CP violation and of natural suppression of the flavor-changing neutral currents. We explain why our work is relevant even for non-Abelian symmetries.engMaximal CP NonconsercationQuark Mass MatricesNeutral CurrentsHiggs DoubletsViolationConservationScalarsjournal article