Abstract
An analysis of the production of a Higgs boson (H) in association with a top quark-antiquark pair (
$$ \textrm{t}\overline{\textrm{t}}\textrm{H} $$
t
t
¯
H
) or a single top quark (tH) is presented. The Higgs boson decay into a bottom quark-antiquark pair (H →
$$ \textrm{b}\overline{\textrm{b}} $$
b
b
¯
) is targeted, and three different final states of the top quark decays are considered, defined by the number of leptons (electrons or muons) in the event. The analysis utilises proton-proton collision data collected at the CERN LHC with the CMS experiment at
$$ \sqrt{s} $$
s
= 13 TeV in 2016–2018, which correspond to an integrated luminosity of 138 fb
−1. The observed
$$ \textrm{t}\overline{\textrm{t}}\textrm{H} $$
t
t
¯
H
production rate relative to the standard model expectation is 0.33 ± 0.26 = 0.33 ± 0.17(stat) ± 0.21(syst). Additionally, the
$$ \textrm{t}\overline{\textrm{t}}\textrm{H} $$
t
t
¯
H
production rate is determined in intervals of Higgs boson transverse momentum. An upper limit at 95% confidence level is set on the tH production rate of 14.6 times the standard model prediction, with an expectation of
$$ {19.3}_{-6.0}^{+9.2} $$
19.3
−
6.0
+
9.2
. Finally, constraints are derived on the strength and structure of the coupling between the Higgs boson and the top quark from simultaneous extraction of the
$$ \textrm{t}\overline{\textrm{t}}\textrm{H} $$
t
t
¯
H
and tH production rates, and the results are combined with those obtained in other Higgs boson decay channels.
