Observation of Higgs boson decay to bottom quarks

TL;DR

This paper reports the first observation of the Higgs boson decaying into bottom quarks with a significance close to the Standard Model prediction, using data from the CMS experiment at 13 TeV.

Contribution

It presents the observation of Higgs to bottom quarks decay in associated production channels, combining multiple datasets for a high-significance result.

Findings

Observed a 4.8 sigma excess at 125.09 GeV for Higgs to bottom quarks.

Combined data yields a 5.6 sigma significance, confirming the decay mode.

Measured signal strength is consistent with the Standard Model expectation.

Abstract

The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.3 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV, are described. When combined with previous VH measurements using data collected at $\sqrt{s}=$ 7, 8, and 13 TeV, an excess of events is observed at $m_\mathrm{H} =$ 125.09 GeV with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is 1.01 $\pm$ 0.22. The combination of this result with searches by the CMS experiment for H $\to\mathrm{b\overline{b}}$ in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of 1.04 $\pm$ 0.20.