We analyse the constraints and some of the phenomenological implications of a class of two Higgs doublet models where there are flavour-changing neutral currents (FCNC) at tree level but the potentially dangerous FCNC couplings are suppressed by small entries of the CKM matrix V . This class of models have the remarkable feature that, as a result of a discrete symmetry of the Lagrangian, the FCNC couplings are entirely fixed in the quark sector by V and the ratio v 2 / v 1 of the vevs of the neutral Higgs. The discrete symmetry is extended to the leptonic sector, so that there are FCNC in the leptonic sector with their flavour structure fixed by the leptonic mixing matrix. We analyse a large number of processes, including decays mediated by charged Higgs at tree level, processes involving FCNC at tree level, as well as loop induced processes. We show that in this class of models one has new physical scalars beyond the standard Higgs boson, with masses reachable at the next round of experiments.
展开▼
机译：我们分析了一类两个希格斯双峰模型的约束和一些现象学上的含义，其中树型结构上存在风味变化的中性电流（FCNC），但潜在危险的FCNC耦合被CKM矩阵V的少量输入所抑制。这类模型的显着特点是，由于拉格朗日离散的对称性，FCNC联轴器完全通过V和中性希格斯的vev的比率v 2 / v 1固定在夸克区中。离散对称性扩展到了轻子扇形区域，因此在轻子扇形区域中存在FCNC，其风味结构由轻子层混合矩阵固定。我们分析了大量过程，包括在树级别由带电希格斯介导的衰变，在树级别涉及FCNC的过程以及环路诱发的过程。我们证明，在这类模型中，有一个新的物理标量超出了标准的希格斯玻色子，并且在下一轮实验中可以达到质量。
展开▼
