Search for associated production of a Higgs boson and a single top quark in proton-proton collisions at $\sqrt{s} =$ 13 TeV

CMS Collaboration

Published 2018-11-23Version 1

A search is presented for the production of a Higgs boson in association with a single top quark, based on data collected in 2016 by the CMS experiment at the LHC at a center-of-mass energy of 13 TeV, which corresponds to an integrated luminosity of 35.9 fb$^{-1}$. The production cross section for this process is highly sensitive to the absolute values of the top quark Yukawa coupling, $y_t$, the Higgs boson coupling to vector bosons, $g_\mathrm{HVV}$, and, uniquely, to their relative sign. Analyses using multilepton signatures, targeting H$\to$WW, H$\to\tau\tau$, and H$\to$ZZ decay modes, and signatures with a single lepton and a $\mathrm{b\overline{b}}$ pair, targeting the H$\to\mathrm{b\overline{b}}$ decay, are combined with a reinterpretation of a measurement in the H$\to\gamma\gamma$ channel to constrain $y_\mathrm{t}$. For a standard model-like value of $g_\mathrm{HVV}$, the data favor positive values of $y_\mathrm{t}$ and exclude values of $y_\mathrm{t}$ below about $-$0.9 $y_\mathrm{t}^\mathrm{SM}$.