Measurement of the Higgs boson production rate in association with top quarks in final states with electrons, muons, and hadronically decaying tau leptons at $$\sqrt{s} = 13\,\text {Te}\text {V} $$ s = 13 Te

Abstract

Abstract The rate for Higgs (

$${\mathrm{H}} $$

H

) bosons production in association with either one (

$${\mathrm{t}} {\mathrm{H}} $$

t H

) or two (

$${\mathrm{t}} {{\overline{{{\mathrm{t}}}}}} {\mathrm{H}} $$

t

t ¯

H

) top quarks is measured in final states containing multiple electrons, muons, or tau leptons decaying to hadrons and a neutrino, using proton–proton collisions recorded at a center-of-mass energy of

$$13\,\text {Te}\text {V} $$

13

Te

by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137

$$\,\text {fb}^{-1}$$

fb

- 1

. The analysis is aimed at events that contain

$${\mathrm{H}} \rightarrow {\mathrm{W}} {\mathrm{W}} $$

H → W W

,

$${\mathrm{H}} \rightarrow {\uptau } {\uptau } $$

H → τ τ

, or

$${\mathrm{H}} \rightarrow {\mathrm{Z}} {\mathrm{Z}} $$

H → Z Z

decays and each of the top quark(s) decays either to lepton+jets or all-jet channels. Sensitivity to signal is maximized by including ten signatures in the analysis, depending on the lepton multiplicity. The separation among

$${\mathrm{t}} {\mathrm{H}} $$

t H

,

$${\mathrm{t}} {{\overline{{{\mathrm{t}}}}}} {\mathrm{H}} $$

t

t ¯

H

, and the backgrounds is enhanced through machine-learning techniques and matrix-element methods. The measured production rates for the

$${\mathrm{t}} {{\overline{{{\mathrm{t}}}}}} {\mathrm{H}} $$

t

t ¯

H

and

$${\mathrm{t}} {\mathrm{H}} $$

t H

signals correspond to

$$0.92 \pm 0.19\,\text {(stat)} ^{+0.17}_{-0.13}\,\text {(syst)} $$

0.92 ± 0.19

(stat)

- 0.13

+ 0.17

(syst)

and

$$5.7 \pm 2.7\,\text {(stat)} \pm 3.0\,\text {(syst)} $$

5.7 ± 2.7

(stat) ± 3.0

(syst)

of their respective standard model (SM) expectations. The corresponding observed (expected) significance amounts to 4.7 (5.2) standard deviations for

$${\mathrm{t}} {{\overline{{{\mathrm{t}}}}}} {\mathrm{H}} $$

t

t ¯

H

, and to 1.4 (0.3) for

$${\mathrm{t}} {\mathrm{H}} $$

t H

production. Assuming that the Higgs boson coupling to the tau lepton is equal in strength to its expectation in the SM, the coupling

$$y_{{\mathrm{t}}}$$

y t

of the Higgs boson to the top quark divided by its SM expectation,

$$\kappa _{{\mathrm{t}}}=y_{{\mathrm{t}}}/y_{{\mathrm{t}}}^{\mathrm {SM}}$$

κ t

=

y t

/

y

t

SM

, is constrained to be within

$$-0.9< \kappa _{{\mathrm{t}}}< -0.7$$

- 0.9 <

κ t

< - 0.7

or

$$0.7< \kappa _{{\mathrm{t}}}< 1.1$$

0.7 <

κ t

< 1.1

, at 95% confidence level. This result is the most sensitive measurement of the

$${\mathrm{t}} {{\overline{{{\mathrm{t}}}}}} {\mathrm{H}} $$

t

t ¯

H

production rate to date.