Search for the Standard Model Higgs boson produced in association with a vector boson and decaying to bottom quarks with the ATLAS detector

This note presents an updated search with the ATLAS experiment for the Standard Model Higgs boson produced in association with a $W$ or $Z$ boson and decaying to $b\bar{b}$ using 4.7 fb$^{-1}$ of LHC data at $\sqrt{s}=7~\mathrm{TeV}$ and 13.0 fb$^{-1}$ at $\sqrt{s}=7~\mathrm{TeV}$. The search is performed using events containing zero, one or two electrons or muons targeting the three decay modes $ZH \to \nu\bar{\nu} b\bar{b}$, $WH \to \ell\nu b\bar{b}$ and $ZH \to \ell^+\ell^- b\bar{b}$. No significant excess is observed. For $m_H = 125$ GeV, the observed (expected) upper limit on the cross section times the branching ratio is found to be 1.8 (1.9) times the Standard Model prediction. The production of diboson pairs, $WZ$ and $ZZ$, with a $Z$ boson decaying to $b\bar{b}$, has been observed with a significance of 4.0 standard deviations at a rate compatible with the Standard Model expectation.