ATLAS SM VH(bb) Run-2 Search

Abstract

The Higgs boson discovered at the LHC in 2012 has been observed coupling directly to $W$ and $Z$ bosons and to $\tau$ leptons, and indirectly to top quarks. In order to probe whether it is indeed the particle predicted by the Standard Model, direct couplings of the Higgs boson to quarks must also be measured. The Higgs boson decays most often to a pair of bottom quarks (with a branching ratio of 58%). When the Higgs boson is produced alone in gluon-gluon fusion, the signal in this decay mode is overwhelmed by the regular multi-jet background. By requiring the Higgs boson to be produced in association with a vector boson $V$ ($W$ or $Z$), which is further required to decay leptonically, data events can be selected using charged-lepton or missing transverse energy triggers. The Tevatron experiments presented combined results showing evidence for the $VH(b\bar{b})$ process at a significance level of about 3 standard deviations, while the combined LHC results from Run-1 data show a 2.6 standard deviation evidence for the $H\rightarrow b\bar{b}$ decay mode. In this poster, the ATLAS $VH(b\bar{b})$ search using Run-2 data is summarised.