Charged-Higgs phenomenology in the aligned two-Higgs-doublet model

The alignment in flavour space of the Yukawa matrices of a general two-Higgs-doublet model results in the absence of tree-level flavour-changing neutral currents. In addition to the usual fermion masses and mixings, the aligned Yukawa structure only contains three complex parameters ς f , which are potential new sources of CP violation [ 1 ]. For particular values of these three parameters all known specific implementations of the model based on discrete symmetries are recovered. One of the most distinctive features of the two-Higgs-doublet model is the presence of a charged scalar H ± . In this work, we discuss its main phenomenological consequences in flavour-changing processes at low energies and derive the corresponding constraints on the parameters of the aligned two-Higgs-doublet model.