Beyond the Standard Model

• Naturalness
• SM Effective Theory
• The Two Higgs Doublet Model

The Higgs sector of the SM is highly predictive. The predictions include

• Coincidence of the cubic and quartic Higgs couplings ${\lambda }_3$ and ${\lambda }_4$
• The absence of flavour-changing neutral scalar currents.

Both of the above are possible in a variety of BSM models. We have seen explicitly that in the 2HDMs, flavour-changing currents can emerge. We have also seen that generic (model-independent) statements can be made for the ratio of ${\lambda }_3$ and ${\lambda }_4$, which is highly constraining e.g. for the coefficients of the SMEFT.