Speaker
Description
It is universally accepted that the Standard Model (SM) is incomplete, and many
models that describe physics Beyond the Standard Model (BSM) has by necessity
an extended Higgs sector. The smallest extensions add one additional Higgs
doublet to the one already present in the SM. These models are collectively
called Two Higgs Doublet Models (2HDM). The scalar particle observed in 2012 is
then understood to be one of two neutral scalar bosons described by the 2HDM,
out of a total of 5 bosons. The remaining 3 are then a neutral pseudo-scalar
and a pair of charged scalar bosons.
The observation of such a charged Higgs boson, $H^\pm$, would be convincing
evidence of BSM physics and numerous direct searches has been carried out by
both ATLAS and CMS. For charged Higgs masses below that of the top quark, the
dominant decay is to a tau-lepton and a corresponding tau-neutrino. As the mass
of the charged Higgs increases, the decay into a top- and a bottom-quark becomes
kinematically allowed and quickly becomes the dominant channel. Thus these two
decay modes naturally complement each other.
This talk presents the latest ATLAS results from the searches for a charged
Higgs boson in the $\tau\nu$ and $tb$ decay channels, using 36.1 $fb^{-1}$ of
proton-proton collision data collected during 2016 and 2017.
