Extra Higgses at LHC: the EW Road to Baryogenesis

Abstract

A cosmological first order electroweak phase transition could explain the origin of the matter-antimatter asymmetry in the Universe. Such a phase transition does not occur in the Standard Model, while it becomes possible with the existence of a second Higgs doublet in Nature. We obtain the properties of the new scalars $H_0$, $A_0$ and $H^{\pm}$ that lead to such a phase transition, showing that its characteristic signature at LHC would be the observation of the decay $A_0 \rightarrow H_0 Z$. We analyze the LHC search prospects for this decay in the $\ell \ell b\bar{b}$ and $\ell \ell W^{+} W^{-}$ final states, showing that either one is promising at the early stages of the 14 TeV run.